### Instruction: What is $56.78-43.6?$.### Response: 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.
I do not need to borrow or carry any digits in this problem.
The decimal point stays in the same place as in the original numbers.
The final answer is 13.18.