Transcript

NARRATOR:

Take this chocolate bar. It has 24 pieces. Each piece is 1 out of 24 of the bar, or 1/24 of the bar. So the whole bar is 24/24, or 1.

There are 4 identical rows. So each row is 1/4 of the bar. There are also 6 identical columns. So each column is 1/6 of the bar.

Now imagine that you eat 8 of the 24 pieces. This is equivalent to 1/3 of the chocolate bar because 1/3 is equal to 8/24. You can visualise this by covering up 2 of the columns.

You are still feeling hungry five minutes later, so you decide to eat another 5 pieces. What fraction of the bar will you have eaten in total? And what fraction of the bar is left?

The fraction eaten would be 1/3 plus 5/24. But it's not easy to quickly determine what fraction this is because the two fractions are out of different numbers of parts. However, if you recall that eating a 1/3 of the bar is the same as eating 8/24, the fraction eaten is 8/24 plus 5/24, which is equal to 13/24. You can check this answer on the bar of chocolate. Just count the number of squares that have been eaten.