Grade 5 · Unit 5: Using units of measurement

Mass

Decimal masses and problem solving.

Jute plants beside a beel in Natore. Jute fibre is weighed and sold in bales.

Shipping jute

Bangladesh exports jute in bales. Each bale might be about 180 kg. Ships carry thousands of tonnes.

Units of mass

1 g = 1000 mg; 1 kg = 1000 g; 1 t = 1000 kg. Medicine doses use milligrams. Ships and trucks use tonnes.

Decimal masses

Read scales carefully between marks. 2.35 kg = 2 kg 350 g. Convert: × 1000 for grams.

Problem solving

20 bales of 180 kg each = 3600 kg. 3600 kg = 3.6 tonnes. Always give the unit.

How accurate?

When the pointer is between marks, estimate: about 2.35 kg. A pharmacist must be very accurate – to the milligram. A farmer selling pumpkins can round to the nearest 100 g. Choose the accuracy the job needs.

What I learnt