# Addition and Subtraction | Primary Math eBook

#### Addition and Subtraction | Primary Math eBook

 6 = 2 + 4 I now have six apples. I receive two more apples. I have four apples.

6    SUM

Step 1: ALWAYS put your numbers into column form, making sure that the ones are properly aligned on the right-most side. If necessary, draw a place value table like the one below:

 Hundred Thousands Ten Thousands Thousands Hundreds Tens Ones 5 7 8 + 3 6 9

Step 2:

Add together the individual numbers, starting with the ONES, and moving to the left side.

578                       8 + 9 = 17, therefore write down 7 and put the 1 in the Tens column

+ 369

7 + 6 = 13, but add the 1 from before and write down the 4 from 14 in the                                       Tens column, and put the 1 in the Hundreds column

Finally, add the 5 and 3, and the 1 from before and write down 9 in the                                             Hundreds column

1 1

578

+ 369

947

## Subtraction

Subtraction means to take away a value from another value.

 6 = 2 - 8 I now have six apples. I give two apples away. I have eight apples.

8       MINUEND

- 2      SUBTRAHEND

6        DIFFERENCE

Step 1: ALWAYS put your numbers into column form, making sure that the ones are properly aligned on the right-most side. If necessary, draw a place value table like the one below:

 Hundred Thousands Ten Thousands Thousands Hundreds Tens Ones 5 3 2 - 1 6 9

Step 2: Subtract the individual numbers, starting with the ONES, and moving to the left side.

532

- 169

2 – 9 is not possible, so we “borrow” a 1 from the 3 in the Tens place (turning the 3 into a 2       as we do so), and treat the 2 as it were a 12. Therefore, 12 – 9 = 3. We write down the 3 in           the Ones column.

Now, we look not at 3 – 6 in the Tens column, but at 2 – 6, because we “borrowed” 1 for the       above step. Likewise, we “borrow” a 1 from the Hundreds column (thus, the 5 now becomes       a 4), and ask ourselves 12 – 6 = 6, of course.

Finally, we take our 5 – which is actually a 4 now – and subtract 4 – 1 = 3.