Download Formal Multiplication – HTU x TU

Formal Multiplication – HTU x TU
Long multiplication extends tables work so that numbers bigger than
10 can be multiplied without using a calculator. There are a number
of ways to do this.
The traditional method is demonstrated in the example below. This
method is very versatile and can handle decimals as well as whole
numbers. In the box on the right you can enter your own
multiplications. Watch as the solution unfolds step by step.
Let's look at doing the sum 12 × 304, which was randomly generated
when you loaded the page.
Of course, we could simply keep adding 304s together until we have
12 lots of 304, but that could take a very long time. Instead, we use
the following method:
Step 1: Set the multiplication out as follows.
3 0 4
×
1 2
Note that the number with the smaller number of digits goes at the
bottom.
Step 2: Multiply 304 by 2.
3 0 4
×
1 2
6 0 8
The result of 2 × 304 is shown in bold.
Step 3: Next, multiply 304 by 10. This is the same as multiplying 304
by 1 and by 10. We place a zero to the right and then write down the
result of 1 × 304.
×
3 0 4
1 2
6 0 8
3 0 4 0
The result of 1 × 304 is shown in bold and the additional zero has
been shown in blue.
Step 4: Finally, add these two rows together to give the final answer.
×
3 0 4
1 2
6 0 8
3 0 4 0
3 6 4 8
The final answer for 12 × 304 is 3648