Sam has 55p. Ben has 10p less than Sam. Tick the coins that Ben has.
And then we’ve got some different coins that we’ve got to choose from. There are two 20p coins. Then we can also see some 10p coins that we could tick. And there are three of those. And the small coin in the middle is a 5p coin. So we’ve got plenty to choose from.
Firstly. we’re told that Sam has 55 pence. 55 contains five tens. Because we’re talking about money, let’s make these into coins and write p on the end. And Sam has five ones as well. And we could write a 5p coin to represent those five ones. We’re told that Ben has 10p less than Sam. What’s 10p less than 55p?
At the moment, Sam’s amount of money is the same as five tens and five ones. If Ben has 10p less than this, he has one lot of 10 less. So let’s erase one of Sam’s 10p coins. This is now the amount that Ben has: four tens and five ones. And the five ones we represent by a 5p coin. Sam has 55p and we now know Ben has 45p.
We’re asked to tick the coins that Ben has. So in other words, the question is asking us, can you tick some coins that equal 45p? We know we definitely need to make five ones. And the only way to make five ones using the coins that we have is by using the five-pence coin. So we can tick that to start with.
Now we need to make four tens. How can we make four tens or 40 pence using the coins that we have? Unfortunately, we can’t use four 10p coins. We only have three 10p coins. So we need to use at least one of the 20 pences in our answer. Let’s tick this one here to show we want to use it. 20 is the same as two tens. To make 40, we need another two tens. So we can tick the other 20-pence coin. 20 plus 20 equals 40. And then if we add the 5p coin too, we get the total we’re looking for, which is 45.
There is another way we could’ve answered this question. Did you spot it? We know we definitely need the 5p coin. And because there are only three 10p coins, we did say we had to have a 20p coin. If you remember, we said we now have two tens and we need four tens. Last time, we just used a 20p coin. But instead, we could use two 10p coins. Doesn’t matter which ones we tick, so we’ll tick this one here and this one here.
Let’s check that we’ve made 45. If we add the two 10ps together, they make 20p. And if we add on the 20 pence that we’ve ticked, our total is now 40p. And that important five pence in the middle takes us to 45p.
Sam has 55p. Ben has 10p less than Sam. And we worked out that this means that Ben has 45p. So we knew we needed to tick 45 pence worth of coins. There are two ways to answer the question. They’re both equally right. Firstly, we could tick the two 20 pences and the five pence coin. And the second correct answer is to tick two 10-pence coins, any two 10-pence coins that is, the 20p coin, and also the 5p coin. Because we can make 45 pence in different ways.