Question

Diya and Leo both write the decimal 2.15 repeating as a fraction. Diya's fraction: 97/45 Leo's fraction: 97/5 Who wrote the correct fraction?

Answer 1

We can solve this without counting too much, like this:

When we look st Diya's fraction: it's about 2 : you can see that the top number is about twice as big as the lower one (compare 90 and 40 for this, 90 is a little more than twice 40)

When we look at Leo's fraction: 97 is a lot more than twice 5!!! To simplify compare 90 and 5: it is definitely at least 10 times bigger (actually 18).

So even if we just "look at" the fractions; Leo's fraction seems too big to be 2.(15).

In fact, his fraction is equal to 19.4

Diya was right!

(and 97/45 is exactly 2.(15).