1. Warm Up Problem
Four potted plants cost $88. What is the price per plant?

2. Estimate Products of Fractions
Lesson 4-1

3. Objectives I can estimate the product of fractions.
I can define compatible numbers and explain how they are useful for estimating.

4. To multiply fractions or find a fraction of a #:
Step 1: Divide by the denominator.
Step 2: Multiply by the numerator.

5. Example 1 Estimate 1 4 x 13. Method 1: Use a Model
1. Divide the bar into 4 sections (total is 12)
2. Each section is of 12, or 3.
Method 2: Use compatible numbers.
13 ≈ 12
12 ÷ 4 = 3
So x 13 is about 3. 3

6. Example 2 Estimate 2 5 of 11. Step 1: 11 ≈ 10
Step 2: Divide by the denominator:
10 ÷ 5 = 2
Step 3: Multiply by the numerator:
2 x 2 = 4
So, of 11 is about 4. 2

7. Got It? Estimate the products for the following problems: 1) 1 5 x 16
2) of 13
3) of 23

8. Estimate by Rounding to 1, 0, or 1 2
If the numerator of a fraction is almost as big as the denominator, round up to 1.
𝟕 𝟖 rounds to 1
If the numerator is much smaller than the denominator, round down 0.
𝟏 𝟖 rounds to 0
If the numerator is close to half of the fraction,
round to 𝟏 𝟐

9. Example 3
Estimate 1 3 x ≈ ≈ x 1 = 1 2 So, 1 3 x 7 9 is about 1 2 .

10. Example 4 Estimate 1 9 x 4 5 . 1 9 ≈ 0 4 5 ≈ 1 0 x 1 = 0
1 9 ≈ 0
4 5 ≈ 1
0 x 1 = 0
So, x is about 0.

11. Got It?
3) x 9 10
4) x 9 10
5) x 1 9

12. Example 5 Estimate the area of the flowerbed. Round each mixed number
to the nearest whole number.
ft ≈15 ft
ft ≈ 6 ft
6 x 15 = 90
So the area is about 90 𝑓𝑡 2 .

13. Got It?
A kitchen measures feet by feet. Estimate the area of the kitchen.

14. Homework Hints
#10. (The fraction of NOT rain) x 90