When we add, we use the word plus. Example: 5 + 10 = 15: Five plus ten is fifteen.
When we subtract, we use the word minus. Example: 15 – 10 = 5: Fifteen minus ten is five.
When we divide, we use the word divide. Example: 60/12 = 5: Sixty divided by twelve is 5.
When we multiply, we use the word multiply. Example: 12 X 5= 60 Twelve multiplied by five is sixty. Or, more often, we use the word times: For example: Twelve times five is sixty.
Now sit in pairs and do the following tasks. You may use a pen a paper to help you, but you should talk through every stage of each task, using the vocabulary you have just learned. For example: Jenny is 165 centimetres tall. How much is that in feet and inches?
Well, one inch is 2.54 (“two point five four”) centimetres. So we have to divide 165 by 2.54, which gives us 64.96 (sixty-four point nine six), or 65 inches if we round it up a little. Now, there are 12 inches to a foot. 5 times 12 is 60, which leaves 5. So Jenny is 5 foot 5 inches tall.
a) How tall are you in feet and inches?
b) Galdhøpiggen rises 2469 metres above sea level. How high is that in feet?
c) What is the volume of your classroom in square feet?