Long Multiplication

Maths Help suggests:

Long multiplication is a way to multiply numbers with 2 or more digits.

Here is an example of a long multiplication of two 2-digit numbers:

37 × 28

First, set out the two numbers in columns like this:

Then (being careful with the columns) work out 8 times 37:

Place a zero in the right-most column on the next row,

then work out 2 times 37:

Finally, add these two rows of working out:

The answer is:

Explanation

To work out   37 × 28   you have separately multiplied
37 × 8     and     37 × 20.

In the second row you worked out 37 × 2 and this explains
the extra 0 you had to put at the end.