Complete the Conversion Steps

Teaching Notes

Focus: Relate Decimal and Whole-Number Products. Use the worked example and teaching sequence below to explain the reasoning before independent practice.

Before You Begin

• Read the numbers and identify the operation.

Teaching Steps for Parents and Teachers

1. First multiply using the digits as whole numbers.
2. Count the decimal places in both original factors.
3. Their total tells you where to place the decimal point in the product.
4. Include leading zeros after the decimal point when needed, then remove unnecessary trailing zeros only when the value stays unchanged.
5. For a blank, identify the missing quantity. Substitute the completed value back into the original statement to check it.

Worked Examples

Evaluate 0.6 × 0.5.

1. Calculate the whole-number product: 6 × 5 = 30.
2. The factors have 2 decimal places altogether. Divide the product by 100.
3. The product is 0.3.

Answer: 0.3

Common Mistakes and How to Help

Do not align decimal points as you would for addition. Multiplying by a positive number less than one makes a positive quantity smaller, so a large answer may indicate a misplaced point.

Estimate the product before calculating. Divide the product by a nonzero factor to check the other factor.

Questions to Check Understanding

• Estimate the product before calculating. Divide the product by a nonzero factor to check the other factor.
• Which step explains your answer?
• Can you apply the same reasoning when the numbers change?

Practice Advice

Work through the example together. Ask the learner to explain the first two problems, then try three independently. Review the first incorrect step before assigning more practice.

Next Practice

• Use New Numbers to practice the same skill with different values.
• If the learner needs help, return to the example and model each step before trying again.