Category: Science

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A massive Primary 5/6 PSLE Science Reality Lab guide to OD600 growth charts: why optical density is a useful proxy for microbial culture density, not a universal exact cell count, and how blanking, range, viability, organism and instrument calibration shape the conclusion.

PSLE Science Reality Lab Vol No.301 | “Passed 1,000 Hours of Salt Spray” — Does That Mean 1,000 Hours of Real-World Life?

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A massive Primary 5/6 PSLE Science Reality Lab guide to salt-spray and accelerated-corrosion claims: why 1,000 test hours are not automatically 1,000 outdoor hours or a fixed service life, and how method, specimen, failure criterion and field correlation control the conclusion.

PSLE Science Reality Lab Vol No.300 | “Geiger Counter = 120 CPM” — Is That 120 µSv/h of Radiation Dose?

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A massive Primary 5/6 PSLE Science Reality Lab guide to Geiger-counter displays: why counts per minute are detector count rate, not automatically microsieverts per hour or radiation dose, and what calibration, background and geometry evidence is needed.

PSLE Science Reality Lab Vol No.299 | “Calibration Chart: R² = 0.99” — Is the Method 99% Accurate?

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A massive Primary 5/6 PSLE Science Reality Lab guide to R² on calibration and model charts: why R² = 0.99 describes fit, not 99% measurement accuracy, and what reference, residual, range and independent-check evidence is still needed.

PSLE Science Reality Lab Vol No.298 | “Catch per Unit Effort Went Up” — Does That Prove There Are More Fish?

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A massive Primary 5/6 PSLE Science Reality Lab guide on catch per unit effort: how a relative abundance index differs from a direct fish census and why catchability and standardisation matter.

PSLE Science Reality Lab Vol No.297 | “Treadwear 400” — Will the Tire Last Exactly Four Times as Long on Any Road?

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