MostPSLEappsmarkanswersrightorwrong.Wetellyourchildwhytheywerewrong.

QUESTION

Mei Ling drank 2/5 of a bottle of juice. Her brother drank 1/3 of the same bottle. What fraction of the juice is left?

Your child added 2/5 + 1/3 by adding tops and bottoms separately to get 3/8 — then subtracted from 1 to get 5/8. The error is at the addition step. To add fractions you must find a common denominator first: 2/5 = 6/15 and 1/3 = 5/15, so together they drank 11/15. What's left is 4/15.

QUESTION

Which of the following materials will be attracted to a magnet?

This is one of the most stubborn P4 misconceptions. 'Metal' is not the same as 'magnetic'. Aluminium, copper, gold, silver, and brass are all metals — but a magnet won't pick any of them up. Only three pure metals are magnetic at room temperature: iron, nickel, and cobalt. (Steel works because it contains iron.)

QUESTION

By the time we ___ at the airport, the plane had already taken off.

When a sentence contains 'had + past participle' (past perfect), the OTHER clause must be in simple past — not present. The plane 'had already taken off' is past perfect, so the arrival must be 'arrived' (simple past). 'Arrive' is present tense and creates a tense mismatch.

QUESTION

A car travels 240 km in 3 hours. What is its average speed?

Your child multiplied 240 × 3 = 720. Speed is distance ÷ time — not distance × time. The trick: ask 'in 1 hour, how far did the car go?' If 240 km took 3 hours, then in 1 hour the car covered 240 ÷ 3 = 80 km. So 80 km/h.

QUESTION

Why do we wear thick clothing in cold weather?

A jacket doesn't HAVE heat to give. Your body produces heat (about 100 watts at rest). Cold air pulls that heat away. A thick jacket is an INSULATOR — it traps a layer of warm air close to your skin and slows the rate of heat loss. The MOE keyword here is 'poor conductor of heat' or 'insulator'.