Name __ Gr. 6 Lesson 2 Estimating Nov_ Products And Quotients Objective: to estimate products...

transcript

Name ____ Gr. 6__ Lesson 2 Estimating Nov_

Products And QuotientsObjective: to estimate products Products And Quotients with decimals.

Products And QuotientsRead the top of page 92 about how much string Bernie needs.

Products And QuotientsRead the top of page 92 about how much string Bernie needs.What does the word “about” mean?

Products And QuotientsRead the top of page 92 about how much string Bernie needs.What does the word “about” mean?“About” means “only an estimate is needed”.

Products And QuotientsRead the top of page 92 about how much string Bernie needs.What does the word “about” mean?“About” means “only an estimate is needed”.How can you use “decimal benchmarks” to help you estimate?

Products And QuotientsRead the top of page 92 about how much string Bernie needs.What does the word “about” mean?“About” means “only an estimate is needed”.How can you use “decimal benchmarks” to help you estimate?Well... 1.15 is closer to 1 than 2, I will multiply ≈

Products And QuotientsRead the top of page 92 about how much string Bernie needs.What does the word “about” mean?“About” means “only an estimate is needed”.How can you use “decimal benchmarks” to help you estimate?Well... 1.15 is closer to 1 than 2, I will multiply ≈ 1m X 6 ≈ 6mBernie will need about 6 metres of string altogether.

Products And QuotientsRead the top of page 92 about how much string Bernie needs.What does the word “about” mean?“About” means “only an estimate is needed”.How can you use “decimal benchmarks” to help you estimate?Well... 1.15 is closer to 1 than 2, I will multiply ≈ 1m X 6 ≈ 6mBernie will need about 6 metres of string altogether.OR better yet, “Bernie will need a little more than 6m of string.”

Products And QuotientsPage 92EXPLORE : Estimate your 2 answers, recording HOW you estimated.

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation:

2)Decimal Benchmarks:

3)Compatible Numbers:

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.

2) Decimal Benchmarks:

3) Compatible Numbers:

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈2) Decimal Benchmarks:

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈ 2 X 8 ≈ 16 NOT Good! Underestimated! 2) Decimal Benchmarks:

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈ 2 X 8 ≈ 16 NOT Good! Underestimated! 2) Decimal Benchmarks: Find which number the decimal is closer to... 3) Compatible Numbers:

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈ 2 X 8 ≈ 16 NOT Good! Underestimated! 2) Decimal Benchmarks: Find which number the decimal is closer to...Ex: 2.73 X 8 ≈

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈ 2 X 8 ≈ 16 NOT Good! Underestimated! 2) Decimal Benchmarks: Find which number the decimal is closer to...Ex: 2.73 X 8 ≈ 3 X 8 ≈ 24 Better! Overestimated, but closer 3) Compatible Numbers:

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈ 2 X 8 ≈ 16 NOT Good! Underestimated! 2) Decimal Benchmarks: Find which number the decimal is closer to...Ex: 2.73 X 8 ≈ 3 X 8 ≈ 24 Better! Overestimated, but closer 3) Compatible Numbers: Use numbers that are easy to use mentally.

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈ 2 X 8 ≈ 16 NOT Good! Underestimated! 2) Decimal Benchmarks: Find which number the decimal is closer to...Ex: 2.73 X 8 ≈ 3 X 8 ≈ 24 Better! Overestimated, but closer 3) Compatible Numbers: Use numbers that are easy to use mentally.Ex: 575.94 / 4 ≈

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈ 2 X 8 ≈ 16 NOT Good! Underestimated! 2) Decimal Benchmarks: Find which number the decimal is closer to...Ex: 2.73 X 8 ≈ 3 X 8 ≈ 24 Better! Overestimated, but closer 3) Compatible Numbers: Use numbers that are easy to use mentally.Ex: 575.94 / 4 ≈ 600 /4 because 60 is a multiple of 4 ≈ 150

Products And QuotientsCONNECT: 3 strategies to estimate:1)Front-end Estimation: simply chop off all digits and only use the place value of the front digit.Ex: 2.73 X 8 ≈ 2 X 8 ≈ 16 NOT Good! Underestimated! 2) Decimal Benchmarks: Find which number the decimal is closer to...Ex: 2.73 X 8 ≈ 3 X 8 ≈ 24 Better! Overestimated, but closer 3) Compatible Numbers: Use numbers that are easy to use mentally.Ex: 575.94 / 4 ≈ 600 /4 because 60 is a multiple of 4 ≈ 150 OR 560/4 because 56 is a multiple of 4 ≈ 140

Products And QuotientsCONNECT: Let’s add a 4th strategy to estimate if you need to round off 2 decimals:4) Over/Under Estimation:

Products And QuotientsCONNECT: Let’s add a 4th strategy to estimate if you need to round off 2 decimals:4) Over/Under Estimation: Round one of the decimals up and to balance that over-estimate, round the other decimal off.Ex #1: 2.87 X 9.14 ≈

Products And QuotientsCONNECT: Let’s add a 4th strategy to estimate if you need to round off 2 decimals:4) Over/Under Estimation: Round one of the decimals up and to balance that over-estimate, round the other decimal off.Ex #1: 2.87 X 9.14 ≈ 3 X 9 ≈ 27

Products And QuotientsCONNECT: Let’s add a 4th strategy to estimate if you need to round off 2 decimals:4) Over/Under Estimation: Round one of the decimals up and to balance that over-estimate, round the other decimal off.Ex #1: 2.87 X 9.14 ≈ 3 X 9 ≈ 27 Ex. #2: 19.389 + 61.704 ≈

Products And QuotientsCONNECT: Let’s add a 4th strategy to estimate if you need to round off 2 decimals:4) Over/Under Estimation: Round one of the decimals up and to balance that over-estimate, round the other decimal off.Ex #1: 2.87 X 9.14 ≈ 3 X 9 ≈ 27 Ex. #2: 19.389 + 61.704 ≈ 20 + 60 ≈ 80

Products And QuotientsPRACTICE on Page 94:#1, #2, #3, #4

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4

e) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4≈ 7 X 9 ≈ 63 Undere) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4≈ 7 X 9 ≈ 63 ≈ 4 X 7 ≈ 28 Under Over e) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4≈ 7 X 9 ≈ 63 ≈ 4 X 7 ≈ 28 ≈ 12 X 5 ≈ 60 Under Over Overe) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4≈ 7 X 9 ≈ 63 ≈ 4 X 7 ≈ 28 ≈ 12 X 5 ≈ 60 ≈ 20 X 4 ≈ 80 Under Over Over Overe) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4≈ 7 X 9 ≈ 63 ≈ 4 X 7 ≈ 28 ≈ 12 X 5 ≈ 60 ≈ 20 X 4 ≈ 80 Under Over Over Overe) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5≈ 10 / 5 ≈ 2 Over

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4≈ 7 X 9 ≈ 63 ≈ 4 X 7 ≈ 28 ≈ 12 X 5 ≈ 60 ≈ 20 X 4 ≈ 80 Under Over Over Overe) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5≈ 10 / 5 ≈ 2 ≈ 12 / 2 ≈ 6 Over Under

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4≈ 7 X 9 ≈ 63 ≈ 4 X 7 ≈ 28 ≈ 12 X 5 ≈ 60 ≈ 20 X 4 ≈ 80 Under Over Over Overe) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5≈ 10 / 5 ≈ 2 ≈ 12 / 2 ≈ 6 ≈ 56 / 7 ≈ 8 Over Under Under

Products And QuotientsP.94:1. Estimate each product or quotient. Which strategies did you use? Tell if your estimate is an overestimate or an underestimate.a)7.01 X 9 b) 3.8 X 7 c) 11.85 X 5 d) 19.925 X 4≈ 7 X 9 ≈ 63 ≈ 4 X 7 ≈ 28 ≈ 12 X 5 ≈ 60 ≈ 20 X 4 ≈ 80 Under Over Over Overe) 9.8 5 f) 12.31 2 g) 56.093 7 h) 225.3 5≈ 10 / 5 ≈ 2 ≈ 12 / 2 ≈ 6 ≈ 56 / 7 ≈ 8 ≈ 200 / 5 ≈ 40 Over Under Over Under

Products And QuotientsP.94:2. Waldo paid $29.85 for 3 admission tickets to the Calgary Tower.Estimate the cost of one admission ticket.

Products And QuotientsP.94:2. Waldo paid $29.85 for 3 admission tickets to the Calgary Tower.Estimate the cost of one admission ticket.$29.85 / 3≈ $30 / 3 ≈ $10One admission ticket to the Calgary Tower is about $10.

Products And QuotientsP.94:3. A pair of ice cleats for ice fishing costs $14.89. About how much will 6 pairs of ice cleats cost? How did you find out?

Products And QuotientsP.94:3. A pair of ice cleats for ice fishing costs $14.89. About how much will 6 pairs of ice cleats cost? How did you find out?$14.89 X 6 ≈ $15 X 6 ≈ $906 pairs of ice cleats cost about $90. I rounded up to $15 and x by 6.

Products And QuotientsP.94:4. Estimate the perimeter of each square. Tell if your estimate is an overestimate or an underestimate. How do you know?a) b) c)

1.3cm 2.1cm 2.6cm

P = 4s or 4 X side= 4 X 1.3 ≈ 4 X 1 ≈ 4cmUnder

1.3cm 2.1cm 2.6cm

P = 4s or 4 X side P = 4s or 4 X side= 4 X 1.3 = 4 X 2.1≈ 4 X 1 ≈ 4cm ≈ 4 X 2 ≈ 8cmUnder Under

1.3cm 2.1cm 2.6cm

P = 4s or 4 X side P = 4s or 4 X side P = 4s or 4 X side = 4 X 1.3 = 4 X 2.1 = 4 X 2.6≈ 4 X 1 ≈ 4cm ≈ 4 X 2 ≈ 8cm ≈ 4 X 3 ≈ 12cmUnder Under Over

Name ____ Gr. 6__ Lesson 2 Estimating Nov_ Products And Quotients Objective: to estimate products...

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Name __ Gr. 6 Lesson 2 Estimating Nov_ Products And Quotients Objective: to estimate products...