Step 6 Lesson 5

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Measurement Conversions

Objectives

To estimate measurements.

To be able to convert units of measure, involving the use of a decimal point.

Resources

Abacus 4 Textbook 1 | Squared paper

Today's Lesson

Main Activity

Look around the room and ask your student to estimate the length of various objects (choose objects that are less than 30 cm). Then ask your student to measure the object to see if their estimate was accurate. In time, your student will become more accurate with estimation of length.

Turn to page 40 in Abacus 4 Textbook 1.

Watch the ‘Measurement conversions’ video. Ask your student what they remember about cm and mm.

1cm = 10mm

2cm = 20mm

2.5cm = 25mm = 2cm 5mm

To convert from cm to mm, use place value to multiply by 10.

For Example:

3.6cm = ___mm

so 3.6cm = 36mm

We can also say 3.6cm = 3cm 6mm.

To convert from mm to cm, use place value to divide by 10.

For Example:

48mm = ___cm

so 48mm = 4.8cm

We can also say 48mm = 4cm 8mm.

Explain that in this context, the ‘tenths’ represents part of one whole cm. Anything to the right of the decimal point is smaller than one cm. When we are talking about measurement, if we want to express something in cm but it is smaller than a whole centimetre, we will need to express it as a decimal.

Ask your student to complete pages 40 and 41.