1. Leonard D. Magee Copyright © 2005 - 2012 all right reserved SUBDITION Subtraction without Borrowing or Regrouping

2. Let’s review subtraction using borrowing or regrouping method. Subtraction with borrowing or regrouping: When trying to subtract numbers, where the minuend of a column is smaller than the subtrahend of that column thus, a unit is taken from the adjacent minuend column to the left.

3. Subtraction with Borrowing or Regrouping 33 33 minuend -15 -15 subtrahend In this example, we can not take 5 from 3, but we can take 5 away from 13, which leaves 8. Now subtract 1 from 2. 2 13 18 =

4. Subtraction without Borrowing or Regrouping Subdition has three basic rules: A) Traditional Rule B) The Five Rule C) The Ten Rule

5. The Traditional Rule

6. Traditional Rule When the minuend for that column is larger than the subtrahend for that column 37 minuend -15 subtrahend In this example, we can take 5 from 7 in the ones column and 1 from 3 in the tens column. This leave us with a difference of 22. 22

7. The Five Rule

8. Subdition without Borrowing or Regrouping (using the Five rule) 33 33 minuend -15 -15 subtrahend In this example, we can not take 5 from 3. But, instead of regrouping, lets add the 5 and 3, which gives us 8. Subtract 1 from the number in the minuend column leaving 2. Now subtract the 1, which leaves us 1. 18 = 2

9. The Ten Rule

10. Subdition without Borrowing or Regrouping (using the Ten rule) 33 33 minuend -18 -18 subtrahend In this example, we can not take 8 from 3. But, instead of regrouping, lets use the Ten rule. First subtract the bottom number from 10. Next add the difference to the top number and record the answer. Subtract 1 from the number to the left in the minuend column leaving 2. Now subtract the 1, which leaves us with 1. 15 = 2 10 -8 2 +

11. Summary

12. When the bottom number is 5, and the top number is less than 5, ‘0,1,2,3,4’. Add the top number to the bottom number (5). Subtract 1 from the top number to the left. The Five Rule

13. When the top number is smaller than the bottom number, and the bottom number is not 5. First subtract the bottom number from 10. Then add the difference to the top number and record the results. Subtract 1 from the top number to the left. The Ten Rule

14. Leonard D. Magee Subdition for the 21th Century http://www.subdition.com Copyright © 2005 - 2012 all right reserved Thank you for your time and consideration!