Adding Money

Adding money is like adding numbers but with a point

Everyday life:

If i want to buy a hotdog that costs 2 euros, and I have 1euro and 50cents and another 50 cents. First I add all my money up and I'll get 2euros. The coins might be different but they were the same value.

Story - sum:

I want to buy a pencil case that costs 1.35c and a biro that costs 50c. If I pay with a 5euro note, how much change will I get? The answer is 3.15c, I found this answer by adding up the prices together and I got 1.85c than I subtracted my answer with 5euro to get 3.15c