Two groups can have the same average and different totals. Two groups can have different averages and still produce the same combined total. A simple average of two class averages can be wrong when the classes contain different numbers of pupils. The arithmetic looks easy; the hidden difficulty is that an average describes a total spread across a count.
This volume develops one PSLE Mathematics habit: keep average, total and count connected. Whenever you see an average, ask what was averaged and how many items were included. If the group size changes, the same average represents a different total. If two groups are combined, use their totals and counts rather than averaging the two averages blindly.
The key relationship is simple: total = average × count. Average = total ÷ count. Count = total ÷ average. The challenge is not the formula; it is using the correct group and count at every stage.
Average belongs to a group
An average score, mass, height or number is tied to the items included in that group.
Do not detach the average from its count.
Same average, different count means different total
Average 8 across 5 items gives total 40; average 8 across 20 items gives total 160.
Same mean does not imply same sum.
Same total, different count means different average
Total 60 across 5 items gives 12; across 10 items gives 6.
Count controls how widely the total is distributed.
Combining groups needs totals and counts
Recover each group total, add totals, add counts, then divide.
Do not average averages unless group sizes are equal or another condition justifies it.
Equal-sized groups are a special case
If two groups contain the same number of items, the combined average is the simple average of their averages.
Know why the shortcut works.
Adding one item changes both total and count
A new score does not simply get averaged with the old average.
Rebuild total first.
Removing one item also changes both
Subtract its value from total and one from count.
Do not subtract the item from the average.
Replacing one value keeps count fixed
Total changes by the difference between new and old values.
This can make average-change questions easier.
Average can stay unchanged while values change
One value can rise while another falls by the same total amount.
Average describes the total, not individual equality.
Average does not imply every value equals it
A class average of 70 does not mean every pupil scored 70.
Avoid turning a summary into individual data.
Median and average are different
A middle value is not automatically the arithmetic mean.
Use the measure the question actually names.
Weighted situations need group size
A larger group contributes more to the combined average.
Its average should not receive the same weight as a smaller group.
Unknown count can be recovered
If total and average are known, divide total by average.
Check that the resulting count makes contextual sense.
Unknown total can be recovered
Average times count gives total.
Label the total’s units clearly.
Change in average can be converted to total change
If count stays fixed, a 2-point rise across 30 pupils means total score rises by 60.
This relationship can simplify multi-step problems.
The combined average must respect bounds
With positive counts, a combined average of two groups lies between their averages.
A result outside the range is a strong error signal.
A group with more members pulls the average more
When group averages differ, the combined mean lies closer to the larger group’s mean.
This gives a quick reasonableness check.
Equal addition to every value shifts the average equally
Adding 3 to every score raises the average by 3.
No need to recompute every individual value.
Equal multiplication scales the average
Doubling every value doubles the total and average.
The count stays fixed.
Changing count can hide missing information
If pupils enter or leave and their scores are unknown, the new average may not be determinable.
Do not invent the missing data.
A six-step average-control routine
- Name the group.
- Write its count.
- Write its average.
- Recover total if needed.
- When groups change, update both total and count.
- Only then calculate the new average or compare groups.
Fifty worked average cases
Average 8, five items
Five items have average 8.
The likely average error is average treated as total. Total=40.
Average needs count. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average 8, twenty items
Twenty items have average 8.
The likely average error is same total assumed. Total=160.
Same average hides different totals. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Two classes same average
Class A 20 pupils average 75; B 40 pupils average 75.
The likely average error is same total assumed. Totals are 1500 and 3000.
Same mean, different group sizes. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Combine 20 at 70 and 30 at 80
Find combined average.
The likely average error is average of 70 and 80 used. Totals 1400 and 2400; combined 3800/50=76.
Group sizes weight the result. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Equal groups
20 pupils average 70; 20 average 80.
The likely average error is weighted process overcomplicated. Combined average=(70+80)/2=75.
Shortcut works because counts equal. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Add one score
Ten scores average 60; add score 80.
The likely average error is (60+80)/2 used. Old total 600; new total 680; count 11; new average 680/11.
Old average is not one score. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Remove one score
Ten scores average 60; remove score 40.
The likely average error is 60-40 used. Old total 600; new total 560; count 9.
Update total and count. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Replace score
Ten scores average 60; replace 40 with 70.
The likely average error is recounting group incorrectly. Total rises by 30 to 630; count stays 10; average 63.
Replacement preserves count. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average rises by 2
30 pupils, average rises by 2.
The likely average error is total rise guessed as 2. Total rises by 60.
Multiply average change by count when count fixed. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Unknown count
Total 360, average 12.
The likely average error is count guessed. 360/12=30.
Total divided by average gives count. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Unknown total
Average 15 across 8 items.
The likely average error is 15+8. 120 total.
Average times count. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Same total different average
Group A total 100 across 10; B total 100 across 20.
The likely average error is same average assumed. 10 versus 5.
Count differs. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Same average after redistribution
Scores 50 and 70 become 55 and 65.
The likely average error is average must change. Both totals are 120, average stays 60.
Individual changes can cancel. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
One score above average
Average 60.
The likely average error is all scores around 60 inferred. A score can be much above or below 60.
Average alone does not reveal spread. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average of averages trap
Groups 10@90 and 90@50.
The likely average error is simple average 70. Combined=(900+4500)/100=54.
Large group dominates. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Combined average closer to larger group
Same case.
The likely average error is surprise at 54. 54 is closer to 50 because 90% of pupils are in that group.
Weighted intuition check. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Add average-valued item
Ten scores average 60; add one score 60.
The likely average error is average change expected. Average remains 60.
Adding a value equal to current average preserves mean. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Add above-average item
Ten average 60; add 80.
The likely average error is average falls guessed. Average rises.
Direction check. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Add below-average item
Ten average 60; add 40.
The likely average error is average rises guessed. Average falls.
Relative value predicts direction. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Remove above-average item
Average 60, remove 80.
The likely average error is average rises guessed. Average falls.
Removing high value lowers total relative to count. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Remove below-average item
Average 60, remove 40.
The likely average error is average falls guessed. Average rises.
Direction logic. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Find missing score
Five scores average 70; four total 260.
The likely average error is average used as missing. Total target 350; missing 90.
Recover total first. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Two groups combine to known mean
20@70 plus x pupils@80 gives combined 75.
The likely average error is counts ignored. Set totals/counts relationship.
The unknown count determines weighting. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average mass
6 objects average 4 kg.
The likely average error is kg per object forgotten. Total mass 24 kg.
Units distinguish average and total. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average pages per day
5 days average 18 pages/day.
The likely average error is rate/total confusion. Total pages 90.
Average rate times days. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average cost per item
8 items average cost $5.
The likely average error is unit cost mistaken for total. Total cost $40.
Per-item basis matters. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Class size changes
Average score 70 for 30 pupils; 5 pupils leave.
The likely average error is new average assumed same. Cannot know new average without scores of leavers.
Missing information matters. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Joining groups same average
Group A avg 60, B avg 60.
The likely average error is combined average uncertain. Combined average is 60 regardless of sizes.
Same mean survives combination. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Joining groups different averages
A avg 60, B avg 80.
The likely average error is combined average outside range. Impossible if counts positive.
Combined average must lie between group averages. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Combined mean exactly midpoint
A avg 60, B avg 80, combined 70.
The likely average error is equal size inferred. For two groups, this indicates equal weighting under ordinary positive counts.
Midpoint can reveal weight relation. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average change with fixed count
Count 25, average from 72 to 76.
The likely average error is change 4 treated as total. Total rises 100.
4×25. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average after bonus
Each of 20 pupils gets 3 bonus marks.
The likely average error is recalculate individually. Average also rises by 3.
Equal addition shifts mean equally. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average after multiplying every value
Every value doubles.
The likely average error is average unchanged guessed. Average doubles.
Scaling all values scales total and mean. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average after mixed change
Some rise, some fall.
The likely average error is direction guessed from one case. Need total net change.
Mean follows total when count fixed. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
New combined group
Three groups different sizes.
The likely average error is average group means equally. Recover each total and total count.
Weight every group by size. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Mean versus median
Data 1,1,1,9.
The likely average error is middle average confused. Mean=3; median=1.
Different statistics. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average whole-number context
Average 2.5 books per pupil.
The likely average error is impossible because books whole. Average may be fractional even when individual counts whole.
Summary can be non-integer. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Count must be whole
Total 100, average 30 gives 3.333 items.
The likely average error is context issue. Such values may be incompatible with whole-item count under exact assumptions.
Check feasibility. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Reverse check
Calculated new average 90 from groups 60 and 80.
The likely average error is not challenged. Impossible for positive group sizes.
Bound check catches error. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Final label
Answer 76.
The likely average error is unitless result. Write 76 marks, kg, pages/day or relevant unit.
Average needs quantity identity. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Unknown new pupil score
20 pupils average 70; one pupil joins; new average 71.
The likely average error is new score guessed as 71. Old total 1400; new total 1491; new pupil scored 91.
Average change across many pupils requires a larger individual contribution. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
One pupil leaves
20 pupils average 70; one leaves; new average 69.
The likely average error is leaver score guessed as 69. Old total 1400; new total 1311; leaver score 89.
Use totals before and after. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Two groups same total
Group A 10 pupils average 12; B 15 pupils average 8.
The likely average error is averages compared only. Both totals equal 120.
Different averages can hide equal totals. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Target average
Five values average 20; a sixth is added so average becomes 22.
The likely average error is new value set to 22. Old total 100; new total 132; sixth value 32.
New member must lift whole group. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Removing average-valued item
Ten values average 50; remove a value of 50.
The likely average error is average expected to change. New average remains 50.
Removing exactly the mean preserves it. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Merging three groups
10@50, 20@60, 30@70.
The likely average error is average of 50,60,70 used. Totals 500+1200+2100=3800 over 60; average 63⅓.
Three unequal weights matter. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average rate over days
Day outputs 10,20,30 items.
The likely average error is total confused. Average output is 20 items/day; total 60 items.
Rate and accumulated amount differ. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average after equal subtraction
Every value decreases by 4.
The likely average error is total recalculated from scratch. Average decreases by 4.
Equal shifts preserve relative structure. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Average and percentage
Average score 80 out of 100.
The likely average error is 80 pupils inferred. 80 is a score level, not a count.
Keep quantity type fixed. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
Plausibility from direction
Add an item far above current average.
The likely average error is new average claimed lower. Impossible.
Direction check gives fast error detection. Write TOTAL, COUNT and AVERAGE as three linked quantities before continuing.
Now ask whether the count changed. If it did, the old average cannot be treated as one ordinary data value.
For delayed transfer, change scores to masses, prices, pages or rates while preserving the same average-total-count relationship.
A combined-class clinic
Class A has 20 pupils averaging 70. Class B has 30 pupils averaging 80. A’s total score is 1400 and B’s is 2400. Combined total is 3800 across 50 pupils, so the combined average is 76.
Why not 75? Because 80 belongs to more pupils. The simple average 75 gives the two class averages equal weight even though the classes are unequal in size.
A quick check is that 76 lies between 70 and 80 and closer to 80, the average of the larger group. This does not prove the answer by itself, but it is a useful plausibility check.
An add-and-remove clinic
Suppose 12 pupils average 65. Their total is 780. A pupil scoring 89 joins, so the new total is 869 across 13 pupils. The new average is about 66.85. The new score is far above the old average, so the mean should rise but remain below 89. Both facts are useful checks.
Now remove a pupil scoring 41 from the original 12. The new total becomes 739 across 11 pupils, giving an average above 65. Removing a below-average value raises the mean. This direction logic can catch a sign or subtraction error quickly.
A seven-day average cycle
- Day 1: recover total from average and count.
- Day 2: recover count from total and average.
- Day 3: add or remove one data value.
- Day 4: combine equal-sized groups.
- Day 5: combine unequal-sized groups.
- Day 6: average-change questions with fixed and changing counts.
- Day 7: delayed mixed problems using scores, mass, cost and rates.
Parents and tutors: ask how many values the average represents
When a learner averages two averages, ask how many data values sit behind each one. If the counts differ, recover totals before combining.
When the learner treats an average as an actual member value, ask whether every individual must equal the mean. Use a small counterexample if necessary.
If the structure is correct but arithmetic fails, repair execution separately. Do not reteach averages when the conceptual link is already secure.
Frequently asked questions
Can I average two averages?
Only directly when the groups have equal sizes, or when another condition makes the weighting equal.
Can average be a decimal when items are whole?
Yes. An average is a summary and can be fractional.
Does the same average mean the same total?
Only if the counts are the same.
What if count changes?
Rebuild total and new count before finding the new average.
How do I check a combined average?
It should usually lie between the group averages when counts are positive.
Why does the larger group matter more?
Because more data values contribute to the combined total.
Official 2026 PSLE Mathematics frame
The 2026 PSLE Mathematics syllabus assesses data analysis, application and reasoning. Average questions require learners to connect summary measures to totals and counts. See the 2026 PSLE Mathematics syllabus.
Continue through eduKate
Use the Primary 6 Mathematics Learning Hub. For the PSLE-to-Secondary bridge, continue through Bukit Timah Tutor’s Primary-to-Secondary Mathematics Transition Hub.
The performance rule
An average is never alone: it belongs to a total and a count. Keep all three connected.
