In this Grade 5 enVision Mathematics lesson from Chapter 4, students learn how to use number sense to correctly place the decimal point in the product of a decimal multiplication problem. The lesson teaches students to reason about the relative size of factors — for example, recognizing that multiplying by a decimal less than 1 produces a product smaller than the other factor — and to use place value logic, such as knowing that tenths times tenths yields hundredths. Students apply these strategies to check and correct decimal placement across a variety of multiplication problems involving decimals.
Section 1
How to Multiply Decimal Numbers
How to multiply decimal numbers:
Step 1. Write the numbers in vertical format, lining up the numbers on the right.
Step 2. Multiply the numbers as if they were whole numbers, temporarily ignoring the decimal points.
Step 3. Place the decimal point. The number of decimal places in the product is the sum of the number of decimal places in the factors. If needed, use zeros as placeholders.
Expand to review the lesson summary and core properties.
Section 1
How to Multiply Decimal Numbers
How to multiply decimal numbers:
Step 1. Write the numbers in vertical format, lining up the numbers on the right.
Step 2. Multiply the numbers as if they were whole numbers, temporarily ignoring the decimal points.
Step 3. Place the decimal point. The number of decimal places in the product is the sum of the number of decimal places in the factors. If needed, use zeros as placeholders.