Grade 4 · Unit 5: Using units of measurement

Mass

Read scales and convert grams and kilograms.

Trucks carry heavy loads measured in tonnes.

Loading a truck

A truck can carry 5 tonnes. 1 tonne = 1000 kg. Smaller things are measured in kg and g.

Reading scales

Find the scale interval: how much each mark is worth. Here, there are marks every 0.25 kg. The needle points to about 1.4 kg = 1400 g.

Converting

Multiply kg by 1000 to get grams. Divide grams by 1000 to get kg. 750 g = 0.75 kg.

Solving problems

The sack of onions is 5 times as heavy as the bag of rice. Total mass: 5 + 25 + 1 = 31 kg. In grams: 31 000 g.

Exact or estimate?

A measure can fall between two numbers: here 1.75 kg. A doctor needs an exact dose of medicine. A cook can estimate a pinch of salt. Choose the tool and unit that give the accuracy you need.

What I learnt