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