Multiplying Decimals

Ignore the decimal points and multiply $6\times 4=24$. Count the total decimal places: 1 in 0.6 and 1 in 0.4, so 2 total. Move the decimal point 2 places to the left, giving 0.24.

Ignore the decimal points and multiply $25\times 2=50$. Count the total decimal places: 2 in 0.25 and 1 in 0.2, so 3 total. Move the decimal point 3 places to the left, giving 0.05.

Ignore the decimal points and multiply $75\times 8=600$. Count the total decimal places: 2 in 0.75 and 2 in 0.08, so 4 total. Move the decimal point 4 places to the left, giving 0.06.

Ignore the decimal points and multiply $32\times 15=480$. Count the total decimal places: 1 in 3.2 and 1 in 1.5, so 2 total. Move the decimal point 2 places to the left, giving 4.8.

Ignore the decimal points and multiply $16\times 375=6000$. Count the total decimal places: 1 in 1.6 and 2 in 3.75, so 3 total. Move the decimal point 3 places to the left, giving 6.

Multiply 15.2 by 8.5. Ignore the decimal points and calculate $152\times 85=12920$. Count the total decimal places: 1 in 15.2 and 1 in 8.5, so 2 total. Move the decimal point 2 places to the left, giving 129.2 kilometres.