Page 117 - Math Smart - 7

This bus is very
i
heavy, think tonnes
is the most suitable
O Read what each learner
unit oP measurement
says about measuring the
Yes this bus A bus IS
I
mass of a bus. is heavy. think we really heavy. It would
should use grams be better to use
O Work in a group.
as our unit oP kilograms to measure
Who do you agree with
measurement. Its mass.
and why?
O Discuss your answer
with the class.

5.21 Estimating measurements

O Spotlight Estimation is a key skill. You are estimating length, capacity and mass when you
ask questions such as:
Basic estimates in real
• Do have enough material to make this dress?
I
life
• Is there enough milk in the fridge for the rest of the week?
• A long ruler is
• How many people can use an elevator that can carry a maximum mass of
approximately 30 cm
1000 kg?
long.
• A long stride is
approximately 1 m Investigate
long.
PAIR WORK
• A teaspoon holds What you need: a ruler, tape measure, bathroom scale, kitchen scale,
approximately 5 ml of measuring jug, measuring spoons, a bag of potatoes, a coffee mug, a bucket,
liquid.
an empty milk carton and a tablespoon.
• A mug holds
approximately 250 ml O Complete the tables.
of liquid.
Difference Did you use a What
• An orange has a mass Actual between suitable base measuring
of about 100 g. Mass Estimate measure estimated unit? Explain Instrument
ment and actual how you did you
measurement estimated. use?
a) A bag of
potatoes
b) A pencil
case
c) An adult
human
body
d) A maths
book
e) A school
bag