Download presentation

1
Estimating Products

2
**Use Compatible Numbers…**

When estimating fractions you can use 2 different strategies. Use Compatible Numbers… …when multiplying a whole number and a fraction. …when multiplying a mixed number and a fraction. 65 3 x 7 16 3 3 x 5 4

3
**Use Compatible Numbers…**

When estimating fractions you can use 2 different strategies. Use Compatible Numbers… …when multiplying a whole number and a fraction. …when multiplying a mixed number and a fraction. Use Rounding… …when multiplying two mixed numbers. …when multiplying a mixed number and a whole number. 17 2 4 9 x 65 7 3 10 x 7 5 2 x 1 16 3 3 x 2 5 4

4
**Whole Number X Fraction**

When to Use What... Type of Problem Example Best Strategy Whole Number X Fraction 5 6 41 x Compatible Numbers

5
**41 35 42 ≈ 5 x 6 5 x 6 Estimation with Compatible Numbers 42 ÷ 6 = 7**

When estimating a product of a fraction and a whole number, use compatible numbers. 41 35 5 ≈ x 6 42 5 42 ÷ 6 = 7 x 7 x 5 = 35 6 Step 1: Find the closest basic math fact to 6 and 41. Step 2: Rewrite the problem with the compatible numbers. Step 3: Divide the whole number by the denominator. Step 4: Multiply the quotient by the numerator.

6
**Whole Number X Fraction Mixed Number X Fraction**

When to Use What... Type of Problem Example Best Strategy Whole Number X Fraction 5 6 41 x Compatible Numbers Mixed Number X Fraction 5 7 x 13 2 9 Compatible Numbers

7
**10 13 14 ≈ x x 2 5 9 7 5 7 Estimation with Compatible Numbers 14 ÷ 7 =**

When estimating a product of a fraction and a mixed number, use compatible numbers. 10 13 5 2 ≈ x 7 9 14 14 ÷ 7 = 2 5 x 2 x 5 = 10 7 Step 1: Find the closest basic math fact to 7 and 13 . Step 2: Rewrite the problem with the compatible numbers. Step 3: Divide the whole number by the denominator. Step 4: Multiply the quotient by the numerator. 2 9

8
**41 13 10 x x x When to Use What... 5 6 5 2 7 9 2 1 3 9 Type of Problem**

Example Best Strategy Whole Number X Fraction 5 6 41 x Compatible Numbers Mixed Number X Fraction 5 7 x 13 2 9 Compatible Numbers Mixed Number X Mixed Number 10 2 3 x 1 9 Round

9
**When estimating a product of mixed numbers, use rounding.**

Estimation with Rounding Think: Think: 2 3 1 2 1 9 1 2 V V Add 1 More! Just Ignore! 3 10 2 1 x 3 9 When estimating a product of mixed numbers, use rounding. 11 3 33 x =

10
When to Use What... Type of Problem Example Best Strategy Whole Number X Fraction 5 6 41 x Compatible Numbers Mixed Number X Fraction 5 7 x 13 2 9 Compatible Numbers Mixed Number X Mixed Number 10 2 3 x 1 9 Round Whole Number X Mixed Number x 4 3 7 Round

11
**7 4 5 7 35 3 x 4 x = Estimation with Rounding V Add 1 More!**

Think: 3 4 1 2 V Add 1 More! 7 4 3 x 4 When estimating a product of a mixed number and a whole number, use rounding. 5 7 35 x =

12
**41 13 10 4 7 x When to Use What... 6 5 2 9 1 3 Best Strategy Example**

Type of Problem Round Whole Number X Mixed Number Mixed Number X Mixed Number Compatible Numbers Mixed Number X Fraction Whole Number X Fraction

13
More Examples

14
**32 12 30 ≈ 2 x 5 2 x 5 Estimation with Compatible Numbers 30 ÷ 5 = 6**

When estimating a product of a fraction and a whole number, use compatible numbers. 32 12 2 ≈ x 5 30 2 30 ÷ 5 = 6 x 6 x 2 = 12 5 Step 1: Find the closest basic math fact to 5 and 32. Step 2: Rewrite the problem with the compatible numbers. Step 3: Divide the whole number by the denominator. Step 4: Multiply the quotient by the numerator.

15
**When estimating a product of mixed numbers, use rounding.**

Estimation with Rounding Think: Think: 3 8 1 2 7 9 1 2 V V Just Ignore! Add 1 More! 8 4 3 7 x 8 9 When estimating a product of mixed numbers, use rounding. 8 5 40 x =

16
**41 35 42 ≈ 5 x 6 5 x 6 Estimation with Compatible Numbers 42 ÷ 6 = 7**

When estimating a product of a fraction and a whole number, use compatible numbers. 41 35 5 ≈ x 6 42 5 42 ÷ 6 = 7 x 7 x 5 = 35 6 Step 1: Find the closest basic math fact to 6 and 41. Step 2: Rewrite the problem with the compatible numbers. Step 3: Divide the whole number by the denominator. Step 4: Multiply the quotient by the numerator.

17
**Closest Basic Math Fact**

Review: Compatible Numbers Compatible numbers allow you to estimate quotients by changing the dividend and the divisor into a basic math fact. Division Problem Closest Basic Math Fact Estimation 98 ÷ 9 99 ÷ 9 = 11 55 ÷ 8 56 ÷ 8 = 7 29 ÷ 7 28 ÷ 7 = 4 40 ÷ 6 42 ÷ 6 = 7 11 ÷ 3 12 ÷ 3 = 4

18
**7 5 5 8 2 4 3 9 Rounding Fractions V V Find you’re your number,**

Look right next door , just ignore, or more, add one more. Think: Think: 1 2 Less than Four or less 2 3 4 9 1 2 1 2 V V 1 2 Five Just Ignore! Add 1 More! 7 5 5 8 2 4 3 9

Similar presentations

© 2023 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google