We've worked with horizontal problems before. By looking at our multiplication problem sideways, we can easily see how multiplying with a tens number gives you a tens number for the answer as well.
Let's try this simple equation: 6 times 7.
If:
Then:
In the first problem, we solved6 times 7 equals 42 (6 × 7 = 42), or 42 ones. In the second problem, we turned 7 into a tens number, 70. When we multiplied 6 times 70, we ended up with 420, or 42 tens. See how it works now? When we multiply by a tens number, the product (answer) is a tens number.
Now, let's try it this way:
If:
8 x 12 = 96
Then:
You can also read 8 times 120 as 8 times 12 tens. The product equals 96 tens, or 960.
Here's a tip: If there is a zero in the ones place (ones column) of one of the numbers, then the answer should have a zero in the ones place as well.
Let's try solving 3 times 90. You see that 90 has one zero. So 90 can also be read as 9 tens. The number sentence 3 times 90 can be read as 3 ones times 9 tens. We know that 3 times 9 equals 27 (3 x 9 = 27). So what is 3 times 90?
If:
3 x 9 = 27
Then:
3 x 90 = 270
This can also be read as 3 times 9 tens equals 27 tens.
