5 Minute Check Complete in your notebook

5 Minute Check Complete in your notebook

5 Minute Check Complete in your notebook = = 10 = 1 2

5 Minute Check Complete in your notebook

5 Minute Check Complete in your notebook = x x 3 7 x x = 21 = 4 21

5 Minute Check Complete in your notebook

5 Minute Check Complete in your notebook = x x 4 3 x x = 24 = 7 24

Monday, Oct 21 Lesson 4.1 Estimate Products of Fractions

Objective: To understand how to estimate the product of fractions and /or whole numbers.

Estimate Products of Fractions At the end of this lesson you should be able to answer the following question. Why is estimating products useful?

Estimate Products of Fractions To multiply fractions, multiply the numerators and multiply the denominators, then simplify if needed. Example x = x 5 = 20 = 10 x =

Estimate Products of Fractions To multiply a fraction and whole number, convert the whole number to a fraction, then multiply as before. Example 2 5 x 14 x = x 1 = 5 = 5 5 x =

Estimate Products of Fractions There are three methods to use to estimate. Each method is used in a specific situation. Method 1 – Estimating the product of a fraction and whole number. Method 2 – Estimating the product of two fractions. Method 3 – Estimating the product of two mixed numbers.

Estimate Products of Fractions 1. When estimating the product of a fraction and whole number use a comparable number for the whole number or the denominator (whichever is larger). The comparable number should be divisible by the smaller number.

Estimate Products of Fractions Estimate: 1 4 x 13

Estimate Products of Fractions Estimate: 1 4 x 13 Which number is larger?

Estimate Products of Fractions Estimate: 1 4 x 13 What number is close to 13, but divisible by 4?

Estimate Products of Fractions Estimate: 1 4 x x 12

Estimate Products of Fractions Estimate: 1 4 x 13 ≈ x 1 = 4 = 3

Estimate Products of Fractions 1 Estimate 4 x 13 ≈ 3 We can also make a model

Estimate Products of Fractions Estimate: 1 7 x 3

Estimate Products of Fractions Estimate: 1 7 x 3 Which number is larger?

Estimate Products of Fractions Estimate: 1 7 x 3 What number is close to 7, but divisible by 3?

Estimate Products of Fractions Estimate: 1 7 x 3 ≈ x 1 = 6 = 2

Estimate Products of Fractions 5 Estimate 6 x 13 (Do this on your own)

Estimate Products of Fractions 5 Estimate 6 x 13 ≈ x 1 = 6 =

Estimate Products of Fractions 2 Estimate 5 x 11 (Do this on your own)

Estimate Products of Fractions 2 Estimate 5 x 11≈ x 1 = 5 = 4

Estimate Products of Fractions 2. When multiplying a fraction by a fraction, an estimate can be determined by rounding the fractions.

Estimate Products of Fractions 2. When multiplying a fraction by a fraction, an estimate can be determined by rounding the fractions. Round up to 1 when the numerator is almost as large as the denominator. Example: 7/8 rounds up to 1

Estimate Products of Fractions 2. When multiplying a fraction by a fraction, an estimate can be determined by rounding the fractions. Round up to 1 when the numerator is almost as large as the denominator. Round to ½ when the numerator is about half the denominator. Example: 3/7 rounds to 1/2

Estimate Products of Fractions 2. When multiplying a fraction by a fraction, an estimate can be determined by rounding the fractions. Round up to 1 when the numerator is almost as large as the denominator. Round to ½ when the numerator is about half the denominator. Round down to zero when the numerator is much smaller than the denominator. Example: 1/5 rounds to 0

Estimate Products of Fractions Can either be estimated up or down 0 ¼ ½ ¾ 1

Estimate Products of Fractions Round the fraction. 3 5

Estimate Products of Fractions Round the fraction ≈ 2 Since 3 is about half of 5, we round to ½.

Estimate Products of Fractions Round the fraction. 1 9

Estimate Products of Fractions Round the fraction. 1 9 ≈ 0 Since 1 is much less than 9, we round to 0.

Estimate Products of Fractions Round the fraction. 9 10

Estimate Products of Fractions Round the fraction ≈ 1 Since 9 is close to 10, we round to 1.

Estimate Products of Fractions Estimate x 9 Round each fraction, then perform the operation.

Estimate Products of Fractions Estimate x x 1= 2

Estimate Products of Fractions Estimate x 5

Estimate Products of Fractions Estimate x 5 0 x 1= 0

Estimate Products of Fractions 3. When estimating the product of two mixed numbers, round the mixed number to the nearest whole number. For example: x x 3= 9

Estimate Products of Fractions Estimate: x 1 6

Estimate Products of Fractions Estimate: x x 2 = 6

Estimate Products of Fractions Recap – When estimating a product of a fraction and whole number, choose a comparable number for the whole number or the denominator of the fraction (which ever is larger) which are in the same multiples list.

Estimate Products of Fractions Recap – When estimating a product of two fractions round the fractions to 0, ½ or 1.

Estimate Products of Fractions Recap – When estimating a mixed number round to the nearest whole number.

Estimate Products of Fractions Why is estimating products useful?

Estimate Products of Fractions Friday is the last day to turn in any missing assignments.

Estimate Products of Fractions Agenda Notes Homework – Homework Practice 4-1 Due Tuesday, Oct 22 Mid Chapter 4 Quiz –Monday, Oct 28