| Hard though this may be to believe, if you | | | | smaller digit and recording a ten. |
| use the following method for addition, you | | | | |
| will greatly increase your speed. | | | | In order to add 6 + 7, you subtract the |
| | | | complement of 7(3) from 6, and record a ten. |
| Add With Complements | | | | 6 - 3 gives 3. The recorded ten makes it 13. |
| | | | |
| The basic rule for the new technique is this: | | | | Or to add 8 + 4, you subtract the complement |
| | | | of 8 (2) from 4 and record a ten. 4 - 2 gives |
| To "add" over ten, subtract the complement of | | | | 2. The recorded ten makes it 12. |
| the larger digit from the smaller digit - and | | | | |
| record a ten. | | | | It is useful to subtract the complement of |
| | | | the larger digit rather than the complement |
| First we need to learn what complements are. | | | | of the smaller. In this way you cut in half |
| Then we will take up how to record tens. Both | | | | the number of complements you have to |
| are easy. | | | | remember at this stage - though the other |
| | | | half of the complements are really only the |
| What is a complement? A complement is simply | | | | same pairs of digits that add up to ten |
| the digit that, added to the digit you have, | | | | turned around. Just as 2 is the complement of |
| adds up to ten. You might say that a | | | | 8, so is 8 the complement of 2. |
| complement is that digit needed (in addition | | | | |
| to the one you have) to complete a ten. | | | | Try it yourself, before going any further. |
| | | | Add 7 9 by subtracting the complement of the |
| For example: The complement of 9 is 1, | | | | larger digit from the smaller digit. The |
| because 9 + 1 is ten. The complementt of 8 is | | | | complement of The complement of 9 is - 7 - is |
| 2, because 8 + 2 is ten. The complement of 7 | | | | -Remember to record a ten. So the answer is |
| is 3, and the complement of 6 is 4, because 7 | | | | 16. I hope that is what you arrived at |
| + 3 is ten and 6 + 4 is ten. Even in your | | | | through the new method, even the first time. |
| sleep you would answer that the complement of | | | | If not, then it hasn't become clear yet. |
| 5 is 5. | | | | Another reading of the article is indicated. |
| | | | |
| Those are all the complements you ever have | | | | Now add 3 + 8. Would you subtract the |
| to remember in adding the longest column of | | | | complement of 8 from 3? What is the |
| figures. There are only five of them: five | | | | complement of 8? Don't forget to record a |
| pairs, you will note, that add up to ten in | | | | ten. |
| the table of possible combinations. | | | | |
| | | | Strange and complex as this system |
| Before learning how to add with complements, | | | | undoubtedly seems at the moment, it is really |
| make doubly sure that you have the idea by | | | | far faster. This is because you are working |
| looking at the following digits and giving | | | | with only the easier half of the forty-five |
| their complements. Try to "read" the | | | | digit combinations, the half that add up to |
| complement of each. | | | | less than ten. |
| | | | |
| 7 6 9 5 8 | | | | Each time you use it, the system will become |
| | | | a little easier and more natural. |
| The way you add with complements takes a bit | | | | |
| of getting used to. But it is one of the most | | | | Add 6 + 5. The complement of 6 is - 5 minus - |
| fascinating and fruitful approaches known to | | | | is - Record a ten. |
| short-cut arithmetic. You "add" two digits | | | | |
| that total more than ten by subtracting the | | | | As you incorporate this method into your life |
| complement of the larger digit from the | | | | you will see what a difference it makes. |