Multiplication of a Decimal by 10, 100, 1000

The working rule of multiplication of a decimal by 10, 100, 1000, etc... are:

1. To multiply a decimal by 10, move the decimal point in the multiplicant by one place to the right.

For examples:

(i) 834.7 × 10

$Multiplication by 10$

Here we multiplied the number 834.7 by 10 so we move 1 place to the right.

Or,

834.7 × 10

= (8347/10) × 10

= 8347/1

= 8347

(ii) 73.5 × 10 = 735

(iii) 100.9 × 10 = 1009

2. To multiply a decimal by 100, move the decimal point in the multiplicant by two places to the right.

For examples:

(i) 98.26 × 100

$Multiplication by 100$

Here we multiplied the number 98.26 by 100 so we move 2 places to the right.

Or,

98.26 × 100

= (9826/100) × 100

= 9826/1

= 9826

(ii) 6.006 × 100 = 600.6

(iii) 0.77 × 100 = 77

3. To multiply a decimal by 1000, move the decimal point in the multiplicant by three places to the right.

For examples:

(i) 793.41 × 1000

$Multiplication by 1000$

Here we multiplied the number 793.41by 1000 so we move 3 places to the right.

Or,

793.41 × 1000

= (79341/100) × 1000

= 79341 × 10

= 793410

(ii) 9.15 × 1000 = 9150

(iii) 0.017 × 1000 = 17

4. To multiply a decimal by 10, 100, 1000, etc. move the decimal point of the multiplicant as many places to the right as there are zeroes in the multiplier.

For examples:

(i) 1854.347 × 10

$Multiplication by 10$

Here we multiplied the number by 10 so we move 1 place to the right.

(ii) 72.4 × 100

$Multiplication by 100$

Here there is only one place after the decimal and 100 has two zeros, so we put one zero at the end of the number.

(iii) 887.43 × 1000

$Multiplication by 1000$

Only 2 places are there after the decimal, but 1000 has 3 zeros, so we put one zero at the end of the number.

Note: Remember that in multiplication of a decimal by 10, 100, 1000, etc. the decimal will be moved to the right by as many places as the number of zeroes in the multiplier and when the number of zeros is more than the digits after the decimal number, then extra zeros must be added to the product.

● Decimal.

Decimal Place Value Chart.

Expanded form of Decimal Fractions.

Like Decimal Fractions.

Unlike Decimal Fraction.

Equivalent Decimal Fractions.

Changing Unlike to Like Decimal Fractions.

Ordering Decimals

Comparison of Decimal Fractions.

Conversion of a Decimal Fraction into a Fractional Number.

Conversion of Fractions to Decimals Numbers.

Addition of Decimal Fractions.