multiplying by 10 by moving the digits left Level 6 Module 1 Multiplying & Dividing by 10, 100 & 1000

© Professor Pete's Classroom. All rights reserved. Index Think Bubble Mathematics: Level 6 Module 1 © Professor Pete's Classroom. All rights reserved.

Think Bubble Math: Level 6 Overview Module 1: 244825_TBM601_xdiv _10_100_1000_.pptx Module 2: 240903_TBM602_Integers .pptx Module 3: 244832_TBM603_xdiv_ by_2_3-digit_nos.pptx Module 4: 241750_TBM604_Fractions _convert_compare.pptx Module 5: 242003_TBM605_Percent .pptx © Professor Pete's Classroom. All rights reserved.

Think Bubble Math Worksheets: Many lessons are supported by corresponding worksheets Purchasers: Included in zip file for download Members: Access via profpete.com in TBM section Some lessons recommend that students use hands-on materials 243504_TBM102_WS_Counting_on_back_1_2_3 © Professor Pete's Classroom. All rights reserved.

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Using Think Bubble Math on a Tablet or Phone Download free PowerPoint app in iTunes or Google Play: iPhone or iPad: Android: Save Think Bubble file to your device You may find it helps to install Microsoft OneDrive, to save and find files If you see a warning about “unsupported content”, you can safely ignore it We include special fonts to improve the presentation’s appearance © Professor Pete's Classroom. All rights reserved.

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(c) Professor Pete's Classroom, 2017. All rights reserved. Multiply and Divide by 10, 100, 1000 ACMNA130 Multiply and divide decimals by powers of 10 ACMNA123 Select and apply efficient mental and written strategies and appropriate digital technologies to solve problems involving all four operations with whole numbers (c) Professor Pete's Classroom, 2017. All rights reserved.

Assumed Prior Knowledge Students should already be able to: Recall all basic multiplication and division facts Explain place value from millions to thousandths Relate decimal fractions to both base ten concepts and to equivalent common fractions Associate base ten materials with the relevant numbers and their symbols (numerals) (c) Professor Pete's Classroom, 2017. All rights reserved.

A Controversial Position DON’T: Tell students to “move the decimal point” when multiplying or dividing by 10, 100, 1000, etc. 27.35 x 1000 = ____________________ DO: Encourage students to think of the meaning behind the process, and to use place value to ascertain the answer Since the number is increasing, move digits left 3 places: Experience and an understanding of base ten numbers leads us to adopt an uncommon approach to this topic Teachers all over the world teach students to “move the decimal point” Students all over the world find this confusing, and fail when trying to apply this brute force procedure without understanding 27 35 27 35 © Professor Pete's Classroom. All rights reserved.

Multiplying and Dividing by 10, 100 and 1000 The number slide is a powerful tool enabling students to see what happens to numbers as they are multiplied or divided by a power of 10 The digits remain in the same order, as they move to a different place Decimal points don’t move; nor should we say add a zero 3.5 x 10 3 5 See our Number Slide Gadget for an online interactive tool that illustrates this idea for multiplying or dividing numbers by 10, 100 or 1000 © Professor Pete's Classroom. All rights reserved.

Accompanying worksheet for Printing Lesson 1, 2, 3 and 4 Duplicate one per 2 students Students can create their own number slide 244826_TBM601_Number_slide (c) Professor Pete's Classroom, 2017. All rights reserved.

Supporting Resources: Resources at profpete.com Gadgets Interactive Software Number Slide (accompanying master) Number Slide Gadget Use Number Slide x 10 100 1000 Number Slide ÷ 10 100 1000 Doubling, Halving 2 Digit Numbers Mentally [PowerPoint TBM501] Number Slide Gadget (c) Professor Pete's Classroom, 2017. All rights reserved.

(c) Professor Pete's Classroom, 2017. All rights reserved. Lesson 1: x10 x100 ACMNA130 Multiply and divide decimals by powers of 10 ACMNA123 Select and apply efficient mental and written strategies and appropriate digital technologies to solve problems involving all four operations with whole numbers (c) Professor Pete's Classroom, 2017. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one place = 3 x 10 30 3 Multiplying by 10 is best illustrated by all the digits moving to the left one place Have students think about whether the answer will be larger or smaller. If larger then the digits move left so the digits have a higher value Discuss with students changes such as there being no decimal places now, or a zero/s appearing in the Ones place to hold the place © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When we multiply a number by 10, the digits move to the left one place = 23 x 10 230 2 3 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one place = 3.5 x 10 35 3 5 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one places = 400.7 x 10 4007 4 0 0 7 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one place = 21,059.08 x 10 210,590.8 2 1 0 5 9 0 8 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one place = 209.17 x 10 2091.7 2 0 9 1 7 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one place = 8900 x 10 89,000 8 9 0 0 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 100 When x 100, the digits move to the left two places 2 x 100 = 200 2 Multiplying by 1o0 is best illustrated by all the digits moving to the left two places Have students think about whether the answer will be larger or smaller. If larger then the digits move left so the digit have a higher value Discuss with students changes such as there being no decimal places now, or a zero/s appearing in the Ones place to hold the place © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 100 When x 100, the digits move to the left two places = 2.1 x 100 210 2 1 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 100 When x 100, the digits move to the left two places = 4135.08 x 100 413,508 4 1 3 5 0 8 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 100 When x 100, the digits move to the left two places = 1,004.025 x 100 100,402.5 1 0 0 4 0 2 5 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10, 100 and 1000 = a) 50.6 x 100 5060 = b) 3000 x 10 30,000 = c) 9393.9 x 10 93,939 = d) 40.041 x 100 4004.1 © Professor Pete's Classroom. All rights reserved.

(c) Professor Pete's Classroom, 2017. All rights reserved. Lesson 2: x 1000 ACMNA130 Multiply and divide decimals by powers of 10 ACMNA123 Select and apply efficient mental and written strategies and appropriate digital technologies to solve problems involving all four operations with whole numbers (c) Professor Pete's Classroom, 2017. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 1000 x 1000 When x 1000, the digits move to the left three places 2 x 1000 = 2000 2 Multiplying by 1000 is best illustrated by all the digits moving to the left three places Have students think about whether the answer will be larger or smaller. If larger then the digits move left so the digit have a higher value Discuss with students changes such as there being no decimal places now, or a zero/s appearing in the Ones place to hold the place © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 1000 When x 1000, the digits move to the left three places = 2040 x 1000 2,040,000 2 0 4 0 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one place = 5610.03 x 10 56,100.3 5 6 1 0 0 3 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 100 When x 100, the digits move to the left two places = 1030.1 x 100 103,010 1 0 3 0 1 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 1000 When x 1000, the digits move to the left three places = 8180.9 x 1000 8,180,900 8 1 8 0 9 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 1000 When x 1000, the digits move to the left three places = 2200.02 x 1000 2,200,020 2 2 0 0 0 2 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one place = 6900 x 10 69,000 6 9 0 0 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 100 When x 100, the digits move to the left two places = 299.09 x 100 29,909 2 9 9 0 9 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10, 100 and 1000 = a) 7844.6 x 100 784,460 = b) 36.905 x 1000 36,905 = c) 32.09 x 10 320.9 = d) 567.03 x 1000 567,030 © Professor Pete's Classroom. All rights reserved.

(c) Professor Pete's Classroom, 2017. All rights reserved. Lesson 3: ÷ 10 ÷ 100 ACMNA130 Multiply and divide decimals by powers of 10 ACMNA123 Select and apply efficient mental and written strategies and appropriate digital technologies to solve problems involving all four operations with whole numbers (c) Professor Pete's Classroom, 2017. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 10 ÷ 10 When ÷ 10, the digits move to the right one place = 48 ÷ 10 4.8 4 8 Dividing by 10 is best illustrated by all the digits moving to the right one place Have students think about whether the answer will be larger or smaller. If larger then the digits move left so the digit have a higher value Discuss with students changes such as there being no decimal places now, or a zero/s appearing in the Ones place to hold the place © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 10 When ÷ 10, the digits move to the right one place = 630 ÷ 10 63 6 3 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 10 When ÷ 10, the digits move to the right one place = 51.8 ÷ 10 5.18 5 1 8 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 10 When ÷ 10, the digits move to the right one place = 2901.6 ÷ 10 290.16 2 9 0 1 6 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 100 When ÷ 100, the digits move to the right two places = 230 ÷ 100 2.3 2 3 Dividing by 100 is best illustrated by all the digits moving to the right two places Have students think about whether the answer will be larger or smaller. If larger then the digits move left so the digit have a higher value Discuss with students changes such as there being no decimal places now, or a zero/s appearing in the Ones place to hold the place © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 100 When ÷ 100, the digits move to the right two places = 3010 ÷ 100 30.1 3 0 1 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 100 When ÷ 100, the digits move to the right two places = 150,051 ÷ 100 1500.51 1 5 0 0 5 1 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 100 When ÷ 100, the digits move to the right two places = 1,000,000 ÷ 100 10,000 1 0 0 0 0 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 10 and 100 = a) 89,550 ÷ 100 895.5 = b) 9,522,380 ÷ 100 95,223.8 = c) 36,800 ÷ 10 3680 = d) 56.4 ÷ 100 0.564 © Professor Pete's Classroom. All rights reserved.

(c) Professor Pete's Classroom, 2017. All rights reserved. Lesson 4: ÷ 1000 and revision ACMNA130 Multiply and divide decimals by powers of 10 ACMNA123 Select and apply efficient mental and written strategies and appropriate digital technologies to solve problems involving all four operations with whole numbers (c) Professor Pete's Classroom, 2017. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 1000 When ÷ 1000, the digits move to the right three places = 2000 ÷ 1000 2 ÷ 1000 2 Multiplying by 1000 is best illustrated by all the digits moving to the left three places Have students think about whether the answer will be larger or smaller. If larger then the digits move left so the digit have a higher value Discuss with students changes such as there being no decimal places now, or a zero/s appearing in the Ones place to hold the place © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 1000 When ÷ 1000, the digits move to the right three places = 1,000,000 ÷ 1000 1000 1 0 0 0 Dividing by 1000 is best illustrated by all the digits moving to the right three places Have students think about whether the answer will be larger or smaller. If larger then the digits move left so the digit have a higher value Discuss with students changes such as there being no decimal places now, or a zero/s appearing in the Ones place to hold the place © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 1000 When ÷ 1000, the digits move to the right three places = 4010 ÷ 1000 4.01 4 0 1 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 1000 When ÷ 1000, the digits move to the right three places = 249 ÷ 1000 0.249 2 4 9 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 1000 When ÷ 1000, the digits move to the right three places = 64,200 ÷ 1000 64.2 6 4 2 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 1000 When ÷ 1000, the digits move to the right three places = 320,000 ÷ 1000 320 3 2 0 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 10 When ÷ 10, the digits move to the right one place = 5500.5 ÷ 10 550.05 5 5 0 0 5 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 10 When x 10, the digits move to the left one place = 7110 x 10 71,100 7 1 1 0 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Dividing by 100 When ÷ 100, the digits move to the right two places = 11,090 ÷ 100 1109 1 1 0 9 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 1000 When x 1000, the digits move to the left three places = 403.03 x 1000 403,030 4 0 3 0 3 © Professor Pete's Classroom. All rights reserved.

© Professor Pete's Classroom. All rights reserved. Multiplying by 100 When x 100, the digits move to the left two places = 90.09 x 100 9009 9 0 0 9 © Professor Pete's Classroom. All rights reserved.

Multiplying and Dividing Large Numbers = a) 3,800,330 ÷ 100 38,003.3 = b) 420.06 x 1000 420,060 = c) 599,300 ÷ 10 59,930 = d) 4,700,260 ÷ 1000 4,700.26 © Professor Pete's Classroom. All rights reserved.

Multiplying and Dividing Large Numbers = e) 97.5 x 100 9750 = f) 8400.9 x 1000 8,400,900 = g) 7603 ÷ 100 76.03 = h) 66,200 ÷ 10 6620 © Professor Pete's Classroom. All rights reserved.