Far and Near | Maths Grade 5 CBSE

Play with it

Six ideas about length

From tiny millimetres to long kilometres. Tap each term to see what it means, with something you can picture.

Explore · Length & distancetap a term

Learn

The three big ideas

Millimetre (mm) — very tiny, like the thickness of a coin. Centimetre (cm) — about the width of your fingernail.
Metre (m) — about the length of a big stride or a cricket bat. Kilometre (km) — a long walk; about 12–15 minutes on foot.
Choose the unit that matches the size: small things in cm, rooms in m, towns and cities in km.

Worked example. Which unit fits each — a pencil, a classroom, the road to the next village?

Pencil → cm; classroom → m; road to the next village → km.

1 cm = 10 mm, 1 m = 100 cm, 1 km = 1000 m.
To go from a bigger unit to a smaller one, multiply (3 m → 3 × 100 = 300 cm).
To go from a smaller unit to a bigger one, divide (5000 m → 5000 ÷ 1000 = 5 km).

Worked example. Change 2 km into metres, and 250 cm into metres.

2 km = 2 × 1000 = 2000 m. 250 cm = 250 ÷ 100 = 2 m 50 cm.

Use a ruler for small things and a measuring tape for longer ones. Start at the 0 mark, not the edge.
Estimating is a smart first guess before you measure — “the table looks about 1 metre wide”.
Estimating helps you spot silly answers (a school bag is not 5 metres tall!).

Worked example. Estimate, then measure: how wide is your maths book?

Guess first — “about 20 cm”. Then place the ruler from 0 and read the mark — say 21 cm. Your estimate was close, so it makes sense.

Common mix-up: muddling cm and m. Saying a room is “5 cm wide” or a pencil is “15 m long” is a clue you picked the wrong unit — picture the size first.

Where you’ll meet it

Length in real life

Height charts

At a check-up your height is read in centimetres (and metres). Comparing this year’s number with last year’s shows how much you have grown.

Sports day

A long jump is measured in metres and centimetres; a running race is set in metres, and a cycle ride in kilometres. The right unit keeps the numbers neat.

Reading a map

Road signs give distances in kilometres. Knowing that 1 km = 1000 m helps you judge how far “2 km to the temple” really is.

Check yourself

Quick quiz

Ten friendly questions — mostly multiple-choice with one assertion–reason — to check that you can use units of length, not just remember them.

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