Introduction
In this activity, we are going to be adding and subtracting some measures.
We’ll need to convert some measures as some objects may be in a different unit of measure.
We’ll need to know these facts:
10 mm = 1 cm
100 cm = 1 m
1,000 m = 1 km
1,000 g = 1 kg
1,000 ml = 1 l
Let’s get started:
A B
Jug A has 2 litres of orange.
Jug B has 400 ml of orange.
How much orange is there altogether?
Answer:
In this question, we need to convert the units of measure so that they are the same.
We know that 1 l = 1,000 ml so 2 l = 2,000 ml
So jug A holds 2,000 ml
Jug A = 2,000 ml
Jug B = 400 ml
2,000 + 400 = 2,400 ml
There is 2,400 ml of orange juice.
We could also convert this back to litres by dividing by 1,000.
2,400 ÷ 1,000 = 2.4 litres.
Let’s have a look at another question:
The chair is 98 cm tall.
How tall would two chairs be?
In this question, we simply need to add 98 cm and 98 cm = 196 cm
Two chairs would measure 196 cm.
Let’s have a look at one more question:
The shopping bag weighs 1,100 g
4 apples weighing a total of 200 g are taken out.
What does the bag weigh now?
To answer this, we need to do a subtraction (subtract the weight of the apples)
1,100 – 200 = 900
The bag now weighs 900 g
Now it’s your turn to have a go at some questions!
