1.3 Subtraction |

## Subtraction: Computing a DifferenceSubtraction is used in two types of situations. The first is "How much is left?" and the second is "How much more is needed?" Some words used in subtraction are "minus", "take away", "less", and "difference". In the figure above, the fire station has 7 shovels. Mark "takes away" 3 shovels. How many shovels are left? Set up the problem as 7 shovels minus 3 shovels. The answer to 7 - 3 is 4 shovels. ## Subtracting Large NumbersExample 2 - Subtracting numbers. Subtract 5342 from 9854. ## "Borrowing" NumbersAs you subtract numbers in the ones, tens, hundreds, etc. position, you might find that the number being subtracted is larger than the one from which you are subtracting. In this case, "borrowing" from the next column to the left is necessary. First, subtract the number in the ones column. Because 4 cannot be taken away from 2, 1 ten must be borrowed to get 12 ones. Now take away 4 from 12 to get 8. ## Subtracting Signed NumbersSigns are important in subtracting numbers. Subtracting a negative number changes the sign of the number subtracted. When subtracting a negative number, the subtraction sign and negative sign together produce a positive number. Subtracting a negative number therefore has the result of adding a positive number. See the examples below. ## Practice1. Subtract 219 from 500. Select the correct answer. 2. Subtract 714 - (-51). Select the correct answer. |