1
Four things to measure
Learner’s Book 1: Unit 12, p. 173
GoalSay what we measure with a ruler, balance scales, a measuring jug and a thermometer.
New words
measure · find out how long, heavy, full or hot something isinstrument · a tool used to measuretemperature · how hot or cold something is
Explanation
We measure things every day. A baker measures how much milk goes into a cake. A nurse measures how tall a child has grown. Before going out, we check how hot or cold it is. Each thing we measure needs its own tool, called an instrument. A ruler measures length. Balance scales measure mass. A measuring jug measures capacity. A thermometer measures temperature.
| we measure | instrument |
|---|---|
| length | ruler |
| mass | balance scales |
| capacity | measuring jug |
| temperature | thermometer |
Worked examples
How long is a pencil? We use a ruler. This pencil starts at 0 and ends at 7, so it is 7 cm long.
How much milk fits in a bottle? We use a measuring jug. We pour the milk in and read the number at the top of the milk.
How heavy is a bag of rice? We use scales. Here the bag balances 6 cubes, so it has the same mass as 6 cubes.
Class activity
Tool hunt: find a ruler, a kitchen scale or balance, a measuring jug and a thermometer at home (or draw them). Say what each one measures. Then pick three things around you and say which tool you would use for each.
Practice
1
Which tool measures length?
a ruler
2
Which tool would you use to see how hot the weather is?
a thermometer
3
Which tool goes with each thing we want to find out?
| to find out | use |
|---|---|
| how heavy a pumpkin is | ? |
| how much water a jug holds | ? |
how heavy a pumpkin is: balance scales; how much water a jug holds: measuring jug
4
You want to know how tall a plant is. Do you use a ruler or a thermometer?
a ruler