How do you multiply 7 x 0.15?

In this lesson you will learn how to multiply decimals by whole numbers by using an area model.

Let’s Review HundredsTens Ones 2 groups of ten = 20 3 single units = 3 1 group of 100 = 100 Ones Hundreds Tens Ones 123

Let’s Review Whole Unit (Ones) Tenths Hundredths

Let’s Review Tenths Hundredths Ones Tenths Hundredths Whole 23

Let’s Review Multiplication is repeated addition 5 x = 15

A Common Mistake Forgetting to take the decimal into consideration when multiplying. 0.1 x 11 ≠ 11

Let’s Review Core Lesson Smart Estimate 7 x x 0.1 is 7 tenths 7 x 0.2 is 14 tenths 14 tenths is written 1.4 Smart estimate: Between 0.7 and 1.4 Around is halfway between 0.1 and x0.15 = 7 ≈ x0.1 = 7 ≈ x0.2

Let’s Review Core Lesson 7 x 0.15 Ones Tenths Hundredths 105 This is a reasonable answer since it is close to my smart estimate

Let’s Review Core Lesson A pencil costs $0.28. How much do 6 pencils cost? $0.28 is close to $.25 Smart estimate: Around $1.50 $ x0.28 = 6 ≈ x0.25

Let’s Review Core Lesson 6 x $0.28 Ones Tenths Hundredths 168 This is a reasonable answer since it is close to my smart estimate

In this lesson you have learned how to multiply decimals by whole numbers by using an area model.

Let’s Review Guided Practice 5 x 0.25

Let’s Review Extension Activities Explain why the answer is a decimal when you multiply a whole number by a decimal.

Let’s Review Extension Activities Estimate the answer and then use an area model to show the multiplication of 4 x 0.35.

Let’s Review Quick Quiz Which area model shows 3 x 0.18? ABCD