6.09 Multiplication by 10

Use the place value table to add 10 to each number.

Put 20 in the place value table and add 10.

The amount in the tens place goes up by one and we get a result of\,30. The units value does not change. We add ten again to complete the pattern by adding 1 to the tens place each time.

The complete pattern is 20,\,30,\,40,\,50,\,60.

We can think of 10\times 4 as 10 groups of 4 just like in the image below that has 10 groups of 4 squares:

The above shape has 40 squares in total.

We can also use a place value table and increase the place value of the 4.

The number 4 has a 4 digit in the units column:

But when we multiply 4 by 10, the 4 moves up in place value to the tens.

To have the correct value we put a place holder of 0 in the units column.

So we get: 10\times 4=40