What is $56.78-43.6?$
To subtract two decimals, I need to line up the decimal points and subtract column by column, starting from the rightmost digit. If there is no digit in a column, I can assume it is zero. For example, 43.6 is the same as 43.60. So I can write the subtraction problem as: 56.78 - 43.60. In the hundredths column, I have 8 - 0, which is 8. In the tenths column, I have 7 - 6, which is 1. In the ones column, I have 6 - 3, which is 3. In the tens column, I have 5 - 4, which is 1. The final answer is 13.18. 