# Question: How Do We Multiply Quickly Decimals By 10 Or 100 Mentally?

## How do you divide a decimal by 100?

To divide a whole or a decimal number by 100, move the decimal point two places to the left.

Note that although a whole number does not have a decimal point, we can always add it at the end of the number.

(For example, 35 and 35..

## What are the factors of 100?

Hence, we have obtained all the factors of 100. They are 1,2,4,5,10,20,25,50 and 100.

## How do we multiply quickly by 10 or 100 mentally?

To multiply a decimal by 10, move the decimal point in the multiplicant by one place to the right. Here we multiplied the number 834.7 by 10 so we move 1 place to the right. 2. To multiply a decimal by 100, move the decimal point in the multiplicant by two places to the right.

## Why does multiplying by 10 move the decimal to the right?

When multiplying a decimal by 10 the amount of zeros increased from the right (naturally) making the decimal point go to the right. But when multiplying by 0.10 the zeros come from the left making the number decrease.

## What are the four rules of decimals?

You should become efficient in using the four basic operations involving decimals—addition, subtraction, multiplication, and division.

## How do you multiply decimals easily?

Multiply the numbers just as if they were whole numbers.Line up the numbers on the right – do not align the decimal points.Starting on the right, multiply each digit in the top number by each digit in the bottom number, just as with whole numbers.Add the products.

## How do you multiply decimals by 1?

Answer: Multiply the numbers just as if they were whole numbers. Line up the numbers on the right – do not align the decimal points. Starting on the right, multiply each digit in the top number by each digit in the bottom number, just as with whole numbers.

## How do you multiply by 100?

To multiply any number by 100, just tag TWO zeros on the end. To multiply any number by 1,000, just tag THREE zeros on the end. Note especially what happens when the number you multiply already ends in a zero or zeros. The rule works the same; you still have to tag the zero or zeros.

## How do you work out 5 divided by 100?

5/100 = 120 = 0.05.

## How do you multiply decimals less than 1?

When multiplying a number by a decimal less than one, the product will be smaller than the number being multiplied. This is because we are finding a fractional amount of a quantity. For example, 0.1 x 0.8 = 0.08, because the question is asking us to find one tenth of eight tenths.

## What is the rule for multiplying by 10?

Lesson Summary Multiplication is repeated addition. When multiplying whole numbers by 10, simply add a 0 to the end of the number. When multiplying decimals by 10, move the decimal point one space to the right.

## What happens when you divide by 10?

So what really happens when you divide by 10? Division is the inverse of multiplication. When you divide a number by 10, each digit moves one place to the right to make it 10 times smaller.

## How do you explain dividing by 100?

To divide by 100, move each digit two place value columns to the right. If the number ends in two ‘0’ digits in the tens and units columns, dividing by 100 has the same effect as removing these digits. To divide by 100, move all digits two place value columns to the right.

## Which is the same as dividing a number by 10?

Multiplying or Dividing Decimals by 10 or 100 If you divide a decimal by 10, the decimal point will move one place to the left. If you multiply or divide by any power of 10, it will move a number of spaces equal to the number of 0’s.