multiplication

Multiplying decimals is just like multiplying whole numbers. The only extra step is to decide how many digits to leave to the right of the decimal point. To do that, add the numbers of digits to the right of the decimal point in both factors.

Multiplying decimals by powers of ten:

To multiply a decimal by 10 (one zero), we move the decimal point one place to the right. If we multiply by 100 (two zeros) we move the decimal point two places to the right,……by 1000 (three zeros)……three places…

Examples:
2.31 · 100 = 231 0.0001 ·1000 = 0.1

Exercise: calculate:

a) 321.11 · 12.1 =

b) 222.22 · 111.1 =

c) 234.678 · 1000 =

d) 0.0033 · 10000 =

Solutions: a) 3885.431; b) 24688.642; c) 234678; d) 33