[The narrator reads out the onscreen text.]

NARRATOR: Question two. Aussie Vaas ice-cream stores nationwide have a variety of 15 flavours of ice-cream available for sale. Each scoop of ice-cream they serve weighs 75.5 grams. Cassandra felt extremely indulgent and asked for three scoops of ice-cream on her waffle cone. How many grams of ice-cream did Cassandra have on her waffle cone?

One scoop of ice-cream weighs 75.5 grams. Cassandra had three scoops, therefore 3 times 75.5 grams of ice-cream.

Method 1. 3 times 75.5 is equivalent to calculating 75.5 plus 75.5 plus 75.5. We know that 75.5 plus 75.5, i.e. double 75.5, is 151. And then we still need to add on an additional 75.5, which gives 226.5 grams.

Method 2. 3 times 75.5 can be thought of as 3 times (75 + 0.5). So we can break up this multiplication and work out what 3 times 75 is plus 3 times 0.5. 3 times 75 is 225. 3 times 0.5 is 1.5. Adding these together gives 226.5 grams.

Method 3. We could simply do a long multiplication. So 75.5 multiplied by 3. 3 times 5 gives 15. Carry the 1. 3 times 5 gives 15, plus 1 is 16. Carry the 1. 3 times 7 is 21, plus 1 is 22. Our initial numbers have one digit after the decimal place, so our answer should also have one digit after the decimal place. Giving 226.5 grams.