5 Minute Check Complete on your homework. Find each sum 1. 4.9 + 3.0 2. 0.796 + 13 Find the difference. 3. 19.86 - 4.94 4. 82 – 67.18

5 Minute Check Complete on your homework. Find each sum 1. 4.9 + 3.0

5 Minute Check Complete on your homework. Find each sum 1. 4.9 + 3.0 4.9 + 3.0 7.9

5 Minute Check Complete on your homework. Find each sum 2. 0.796 + 13

5 Minute Check Complete on your homework. . Find each sum 2. 0.796 + 13 13.000 Annex zeros, if needed. + 0.796 13.796

5 Minute Check Complete on your homework. Find the difference. 3. 19.86 - 4.94

5 Minute Check Complete on your homework. Find the difference. 3. 19.86 - 4.94 19.86 - 4.94 14.92

5 Minute Check Complete on your homework. Find the difference. 4. 82 – 67.18

5 Minute Check Complete on your homework. Find the difference. 4. 82 – 67.18 82.00 Annex zeros - 67.18 14.82

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Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Complete in your notebook.

Lesson 3.2/3.3 Estimating and Multiplying Decimals by Whole Numbers Thursday, Oct 1 Lesson 3.2/3.3 Estimating and Multiplying Decimals by Whole Numbers

Multiplying Decimals by Whole Numbers Lesson 3.2 is estimation and will be incorporated into lessons 3.3 and 3.4.

Multiplying Decimals by Whole Numbers Objective: To understand how to estimate and find products of decimals and whole numbers.

Multiplying Decimals by Whole Numbers To multiply a decimal and whole number, multiply as normal and then place the decimal point.

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. First, round the numbers to the nearest whole number and multiply to get an estimate.

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. Which is .93 closest to? 0 .93 1 Digits from 0 to 4 round down and digits from 5-9 round up.

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. Which is .93 closest to? 0 .93 1 6 x 1 = 6, so 6 x .93 ≈ 6

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. To Multiply Decimals. Step 1 – Stack the numbers with the number with the most digits on top.

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. To Multiply Decimals. Step 1 – Stack the numbers with the number with the most digits on top. .93 x 6 Decimals points do NOT need to be lined up when multiplying.

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. To Multiply Decimals. Step 2 – Multiply the digits without regard to the decimal points.

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. To Multiply Decimals. Step 2 – Multiply the digits without regard to the decimal points. .93 x 6 558

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. To Multiply Decimals. Step 3 – Determine the number of decimal places in the factors to locate the decimal point in the product.

Multiplying Decimals by Whole Numbers Find the product of 6 and .93. To Multiply Decimals. Step 3 – Determine the number of decimal places in the factors to locate the decimal point in the product. .93 2 decimal places x 6 0 decimal places 5.58 2 decimal places Is this a reasonable answer?

Multiplying Decimals by Whole Numbers Find the product of 4 and .83. Is this a reasonable answer? 5.58 ≈ 6

Multiplying Decimals by Whole Numbers Find. 5 x 10.2 Estimate?

Multiplying Decimals by Whole Numbers Find. 5 x 10.2 ≈ 50 Estimate? Step 1 - ? 10

Multiplying Decimals by Whole Numbers Find. 5 x 10.2 ≈ 50 10.2 x 5 Step 2 - ? 10

Multiplying Decimals by Whole Numbers Find. 5 x 10.2 ≈ 50 10.2 x 5 510 Step 3 - ? 10

Multiplying Decimals by Whole Numbers Find. 5 x 10.2 ≈ 50 10.2 1 decimal place x 5 0 decimal place 51.0 1 total decimal place 10

Multiplying Decimals by Whole Numbers Find. 5 x 10.2 ≈ 50 10.2 1 decimal place x 5 0 decimal place 51.0 1 total decimal place Does this seem reasonable? 10

Multiplying Decimals by Whole Numbers Find. 5 x 10.2 ≈ 50 10.2 1 decimal place x 5 0 decimal place 51.0 1 total decimal place Does this seem reasonable? Yes, since 50 ≈ 51 10

Multiplying Decimals by Whole Numbers Find. 7 x 7.5 Do this on your own.

Multiplying Decimals by Whole Numbers Find. 7 x 7.5 Estimate?

Multiplying Decimals by Whole Numbers Find. 7 x 7.5 ≈ 56 Actual? 8

Multiplying Decimals by Whole Numbers Find. 7 x 7.5 ≈ 56 7.5 1 decimal place x 7 0 decimal place 52.5 1 total decimal place Does this seem reasonable? 8

Multiplying Decimals by Whole Numbers Find. 7 x 7.5 ≈ 56 7.5 1 decimal place x 7 0 decimal place 52.5 1 total decimal place Does this seem reasonable? Yes, since 52.5 ≈ 56 8

Multiplying Decimals by Whole Numbers Find. 1.2 x 45 Do this on your own.

Multiplying Decimals by Whole Numbers Find. 1.2 x 45 Estimate?

Multiplying Decimals by Whole Numbers Find. 1.2 x 45≈ 45 Actual? 1

Multiplying Decimals by Whole Numbers Find. 1.2 x 45≈ 45 1.2 x 45 60 480 54.0 1 This is how your homework should look. You will need to round the decimal, add the ≈ , and estimate. You will need to show work and circle answer.

Multiplying Decimals by Whole Numbers Find. 5 x .02 ≈ Do this on your own.

Multiplying Decimals by Whole Numbers Find. 5 x .02 ≈ Estimate?

Multiplying Decimals by Whole Numbers Find. 5 x .02 ≈ 0 Actual?

Multiplying Decimals by Whole Numbers Find. 5 x .02 ≈ 0 .02 x 5 0.10 This is how your homework should look. You will need to round the decimal, add the ≈ , and estimate. You will need to show work and circle answer.

Multiplying Decimals by Whole Numbers A sheet of printer paper is 8.5 inches by 11 inches. What is the area of the paper? (Hint: area = length x width) (Do this on your own)

Multiplying Decimals by Whole Numbers A sheet of printer paper is 8.5 inches by 11 inches. What is the area of the paper? (Hint: area = length x width) 8.5 x 11 ≈ 99 8.5 x 11 85 850 93.5 9

Multiplying Decimals by Whole Numbers A pack of baseball cards costs $1.20 and you want to buy 5 packs. If you already have $2, how many more dollars do you need? Do this on your own.

Multiplying Decimals by Whole Numbers A pack of baseball cards costs $1.20 and you want to buy 5 packs. If you already have $2, how many more dollars do you need? 1.2 1 decimal place x 5 6.0 1 decimal place $6 (5 packs) – $2 (you have) = $4

Multiplying Decimals by Whole Numbers A bee hummingbird has a mass of 1.8 grams. How many grams are 6 hummingbirds and a 4 gram nest? Do this on your own.

Multiplying Decimals by Whole Numbers A bee hummingbird has a mass of 1.8 grams. How many grams are 6 hummingbirds and a 4 gram nest? 1.8 1 decimal place x 6 10.8 1 decimal place + 4. (nest) 14.8 g total

Multiplying Decimals by Whole Numbers Find two different ways to find the value of the expression 5.7 x 1.17 x 100 that do not require you to first multiply 5.7 x 1.17. Do this on your own.

Multiplying Decimals by Whole Numbers Find two different ways to find the value of the expression 5.7 x 1.17 x 100 that do not require you to first multiply 5.7 x 1.17. Two possible answers. 1.17 x 100 = 117 x 5.4 = 666.9 5.7 x 100 = 570 x 1.17 = 666.9

Multiplying Decimals by Whole Numbers Use the product of 123 x 47 to find the product of 123 x 0.47. Explain the difference between the two products. Do this on your own.

Multiplying Decimals by Whole Numbers Use the product of 123 x 47 to find the product of 123 x 0.47. Explain the difference between the two products. 123 123 x 47 x .47 861 861 4920 4920 5781 57.81 The products are different by a factor of 100.

Multiplying Decimals by Whole Numbers Your friend thinks that 1.5 x 8 = 1.20 because you do not count the zero when placing the decimal point. Is your friend correct? Explain. Do this on your own.

Multiplying Decimals by Whole Numbers Your friend thinks that 1.5 x 8 = 1.20 because you do not count the zero when placing the decimal point. Is your friend correct? Explain. No, you need the zero to place the decimal point. But you can “unannex” the zero after you place the decimal point.

Multiplying Decimals by Whole Numbers Complete pages 197, #1 – 8 in your book. Bring to my desk when complete. Agenda Notes Homework Homework Practice 3.3 Due Friday, Oct 2 Show all work and circle all answers! Mid-Chapter 3 Quiz - Monday, Oct 5