Coaching Centre
Multiplying and dividing decimals
Multiplying and dividing decimals by powers of 10, by whole numbers and by other decimals.
Powers of 10
$3.68 \times 100 = 368$ and $45.2 \div 1000 = 0.0452$.
Multiplying decimals
Find $0.6 \times 0.07$.
Ignore the points: $6 \times 7 = 42$.
The answer has $3$ decimal places: $0.042$.
One decimal place plus two decimal places.
Dividing decimals
Find $7.56 \div 0.4$.
$75.6 \div 4$
Multiply both numbers by 10 so the divisor is whole.
$= 18.9$
$ imes 100$
Move the point 2 places right.
$0.3 imes 0.2$
$0.06$
Dividing by a decimal
Make the divisor whole by multiplying both by 10, 100, ...
Find $0.6 \times 0.07$.
$42$ with $3$ decimal places.
Find $7.56 \div 0.4$.
$75.6 \div 4$.
Find $3.68 \times 100$.
Two places right.
Find $45.2 \div 1000$.
Three places left.
Find $0.3 \times 0.2$.
$6$ with $2$ decimal places.
Find $2.5 \times 3$.
$25 \times 3 = 75$, one decimal place.
Find $2 \div 0.05$.
$200 \div 5$.
Petrol costs $\$1.875$ per litre. Find the cost of $6$ litres in dollars.
$1.875 \times 6$.
New numbers every time. Keep going until you get five in a row.