Subtracting One Number from Another
[ Remember that if you don’t have enough in one column to perform the subtraction, you will redistribute (or borrow) from the place holder to the left. ] Let’s determine how much money we’d have left over from the previous example.
Write out the calculation so that the decimal points and the corresponding columns line up, making sure the number you are subtracting is on the bottom. Then, subtract the bottom number from the top number in each column, starting at the right and changing the amounts in each column as needed.
If you would like a more detailed explanation of how to perform subtraction using this method, take a look at the subtraction pencast (Click on “View document”)
You may already be familiar with other ways of subtracting numbers. This is fine; just make sure that you can use either this method or your own confidently. Remember, you can check your answer ($9.03) by adding it to the number you subtracted ($16.87)—you should end up with the number you started with ($25.90).
Carry out the follow subtractions on paper.
(a) 526 – 327
(a) 526 – 327 = 199
(b)1029 – 822
(b) 1029 – 822 = 207
(c) 776 – 389
(c) 776 – 389 = 387
(d) 429 – 338
(d) 429 – 338 = 91
How did you get on with that activity? If you think that you need to practice these skills further try applying them to real-life situations, making up some examples of your own or asking friends and family for some. You can check the answers on your calculator.