# Video: Representing Teen Numbers Using Cards

Pick the set of cards that shows 18 hearts.

02:12

### Video Transcript

Pick the set of cards that shows 18 hearts.

Now, when we’re talking about the number of hearts that’re drawn on each of these cards, we’re talking about the large hearts in the middle. The A on this card stands for the word ace. Even if you don’t know what the word ace means, we can work it out by looking at the number of hearts in the middle. And an ace stands for the number one. It’s worth one. So our first set of cards have a value of one and eight. Now, we’re looking for a set of cards that shows 18 hearts. And we do write the number 18 by writing a one and an eight next to each other. So does this mean we can see 18 hearts in the first set? No, if we add one and eight together, we get a total of nine. We can see nine hearts in the first set. This can’t be right.

Our second set of cards shows one, then another card with one heart on it, and then a card with eight hearts on it. Does one, one, and eight make 18? Well, as we’ve already said, one and eight go together to make nine. And if we add the other heart, we have a total of 10 hearts altogether, not 18. Our last set of cards shows the number 10 and eight. And we know that 10 ones plus another eight ones gives us a total of 18 ones. This set of cards must be the one that shows 18 hearts. We know that the first card shows 10 hearts, so let’s treat this as a group of 10 ones and start counting from there. 11, 12, 13, 14, 15, 16, 17, 18. The set of cards that show 18 hearts is the one that contains a group of 10 hearts and then a group of eight hearts.