Suppose you want to add 12.96, 3.5 and 8.

Line up the decimal points.

Begin adding from the right-hand column. Treat the blank spaces after 3.5 and 8 as zeroes.

Add first column.

Continue to the left.

Complete the problem column by column, and at the end, put the decimal point directly below the others. Continue reading Adding Decimals

## Dividing Integers

Suppose you want to find 45 divided by 3.

Start off by writing the problem like this.

To begin, ask how many times 3 goes into 4 — that is, what’s 4 divided by 3? Continue reading Dividing Integers

## Subtracting Integers

Suppose you want to subtract 83 – 56.

Begin subtracting in the ones column: 3 – 6.

Because 3 is smaller than 6, you need to borrow from the tens column.

Subtract 1 from the 8 replacing 8 with a 7.

Continue reading Subtracting Integers

## Adding Large Numbers in Columns

Suppose we want to add 26 and 79

Stack the numbers one on top of another so that the ones digits line up in a column and the tens digits line up in another column.

Add column by column, starting from the ones column on the right. Continue reading Adding Large Numbers in Columns

## Multiplying Larger Numbers

Suppose we want to multiply 57 by 13. First we multiply 57 by 3 to get 171 .

Next we multiply 57 by 1..

1 is in the tens column so it really means 10. We have to put a 0 directly under the 1 in 171.

Now we can multiply 57 by 1 to get 57.

To finish up, add the two products

So 57 multiplyed by 13 is 741. Continue reading Multiplying Larger Numbers

## Multiplying Large Numbers

Suppose we want to multiply 45 by 8. Start by stacking these numbers one on top of another with a line underneath. Multiply 8 by 5 . 8 by 5 is 40 so write down the 0 and carry the 4. Next, multiply 8 by 4. 8 by 4 is 32 . We need to add the 4 that we carried over, which makes the result 36. Because 8 and 4 are the last numbers to multiply, we write down the 36, we don’t have to carry. We find that 45 multiplied by 8 is 360. Continue reading Multiplying Large Numbers