Year 3 Mathematics - Length (Intro)

Measurement Centuries ago, technologies weren’t as advanced as they are today,

and as such, the methods of measuring weren’t accurate.

This is mainly due to the differences in units used by different parts of the world. Examples being, some parts used arm-length as the standard to measure length while other places might consider rice grains to measure smaller lengths.

Measurement Today, accurate measurements are obtained with the use of better

methods and instruments.

Measurement

In the year 1960, scientists from different parts of the world have agreed and

adopted a single system of units called the International System Unit, commonly referred to as SI Units.

Prefixes are usually used with SI units to change them by a factor of ten into either smaller or larger units.

Metric Ruler

A metric ruler is a ruler which based on International System Of Units(SI), sometimes called the metric system.

Metric Ruler

It is divided into either milimetres or centimetres. Rulers are often 30 cm long.

Measuring Tape

Measuring tapes can be used for measuring distances and lengths up to several hundred meters. For example, they are used to measure the distance an athlete throws a discus, shot put or javelin.

Retractable Measuring Tape

=200cm+10 cm =2m+10cm =2m 10 cm =100cm+6 cm =1 m+ 6 cm =1m 6cm

200 cm =(200÷100)m =2m

60 m =____cm = 60x100 =6000cm

7m =______cm =7x100m =700cm

10 m=______cm

2m=______cm

Peggy

169 cm=__m__cm

Jamal 135cm=__m__cm

Peggy

169 cm=2m69cm

Jamal

135cm=1m35cm

The length of a sofa is 3m 10 cm.

What is its length in centimetres?

The length of a sofa is 3m 10 cm.

What is its length in centimetres?

3m 10cm = (3 x100) cm +10cm =310cm

20

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What is the length of the bed?