Multiplying and dividing decimals

What this chapter teaches

To multiply decimals, multiply as whole numbers, then write the answer with as many decimal places as both numbers have together, and drop zeros at the end. A tenth of a tenth is a hundredth. An estimate shows if the point is in the right place. To divide a decimal by a whole number, keep the point in line and carry on with the tenths.

Three questions to ask

There is no one right wording. Listen for the idea.

1. Why is 0.3 × 0.2 equal to 0.06 and not 0.6?
2. How can an estimate show that 4.1 × 2.9 cannot be 118.9?
3. When you work out 7.5 ÷ 3, what do you do with the 1 that is left over from the ones?

After the chapter, the learner can

• Multiply a decimal by a whole number, like 2.4 × 3
• Multiply two decimals, like 0.3 × 0.2
• Divide a decimal by a whole number, like 7.5 ÷ 3