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# Multiplying Multi-Digit Whole Numbers

Multiplying Multi-Digit Whole Numbers. 5 .NBT.B. 5. Multiplying Multi-Digit Whole Numbers. 5. 7. 3. 3. 8. 8. ×. 7. 7. 9. 9. 1. 3. 4. 2. 1. +. 2 6. 6. 0. 3. ,. 0. 0. 2. Here is 38 times 79. Let’s begin by multiplying 38 by 9. What is 9 times 8?. 72.

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## Multiplying Multi-Digit Whole Numbers

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1. Multiplying Multi-Digit Whole Numbers 5 7 3 3 8 8 × 7 7 9 9 1 3 4 2 1 + 2 6 6 0 3 , 0 0 2 Here is 38 times 79. Let’s begin by multiplying 38 by 9. What is 9 times 8? 72 Let’s mark the 2 … … and regroup the 7. Here is 72. The answer is 3,002. Let’s add the 7. What is 27 plus 7? … and regroup the 5. 34 Now, let’s prepare to multiply 38 times 7. First, let’s cross off the regrouped digit. Notice that the 7 is in the tens place, not the ones place. So, let’s mark the ones place with a zero. What is 7 times 8? 56 Let’s mark the 6 … 27 Here is 56. 10 … and regroup the 1 … Let’s add the 5. What is 21 plus 5? 26 Now, let’s add the partial products. What is 2 + 0? 2 What is 4 + 6? What is 7 times 3? Let’s mark the 0 … … so that it still says 10. What is 1 + 3 + 6? 10 Let’s mark the 0 … … and regroup the 1 … … so that it still says 10. What is 1 + 2? 3 Now, let’s mark the comma. 21 What is 9 times 3?

2. Multiplying Multi-Digit Whole Numbers 38 × 79 = 3,002 79 × 38 = 3,002 3,002 3,002 ÷ 38 = 79 38 79 3,002 ÷ 79 = 38 Since we know that 38 x 79 … … is equal to 3,002 … … we also know that 79 x 38 … … is equal to 3,002. 3,002 divided by 38 … … is equal to 79. And, 3,002 divided by 79 … … is equal to 38.

3. Multiplying Multi-Digit Whole Numbers 1 2 5 5 3 3 × 4 4 7 7 3 7 1 + 21 2 0 2 , 4 9 1 Let’s begin by multiplying 53 by 7. What is 7 times 3? 21 Let’s mark the 1 … The product is 2,491. Let’s mark the 2 … 35 Here is 53 times 47. Let’s add the 2. What is 35 plus 2? 37 Now, let’s prepare to multiply 53 times 4. First, let’s cross off the regrouped digit. Notice that the 4 is in the tens place, not the ones place. So, let’s mark the ones place with a zero. Here is 21. What is 4 times 3? What is 7 + 2? 1 And, here is 2. 4 What is 3 + 1? 9 What is 7 times 5? … and regroup the 1. 12 What is 1 + 0? 21 Let’s add the 1. What is 20 plus 1? 20 What is 4 times 5? Here is 12. Now, let’s mark the comma. Now, let’s add the partial products. … and regroup the 2.

4. Multiplying Multi-Digit Whole Numbers 53 × 47 = 2,491 47 × 53 = 2,491 2,491 2,491 ÷ 53 = 47 53 47 2,491 ÷ 47 = 53 Since we know that 53 x 47 … … is equal to 2,491 … … we also know that 47 x 53 … … is equal to 2,491. 2,491 divided by 53 … … is equal to 47. And, 2,491 divided by 47 … … is equal to 53.

5. Multiplying Multi-Digit Whole Numbers 4 3 6 × 9 7 3 0 5 2 + 3 9 2 4 0 4 2,2 92 Here is 436 x 97. Now, we can add the partial products. Next, we multiply 436 x 9. This part of the product is 3,052. So, 42,292 is the product of 436 x 97. These are the partial products to add together. The sum of the partial products is 42,292. Since the 9 is in the tens place, we will mark the ones place with a 0. 436 x 9 = 3,924 The first step in solving this problem is to multiply 436 x 7.

6. Multiplying Multi-Digit Whole Numbers 6 2 9 × 5 8 4 2 5 1 6 5 0 3 2 0 + 3 1 4 5 0 0 3 6 7,3 3 6 Here is 629 x 584. Since the 5 is in the hundreds place, we will mark the ones and tens places with 0. Next, we multiply 629 x 8. Since the 8 is in the tens place, we will mark the ones place with a 0. 629 x 8 = 5,032 629 x 5 = 3,145 The sum of the partial products is 367,336. So, 367,336 is the product of 629 x 584. Now, we can add the partial products. Next, we multiply 629 x 5. These are the partial products to add together. This part of the product is 2,516. The first step in solving this problem is to multiply 629 x 4.

7. Multiplying Multi-Digit Whole Numbers Closing Question

8. Multiplying Multi-Digit Whole Numbers 1 0 8 × 3 7 4 4 3 2 7 5 6 0 + 3 2 4 0 0 4 0,3 9 2 Here is 108 x 374. Since the 3 is in the hundreds place, we will mark the ones and tens places with zeros. Next, we multiply 108 x 7. Since the 7 is in the tens place, we will mark the ones place with a 0. 108 x 7 = 756 108 x 3 = 324 The sum of the partial products is 40,392. So, 40,392 is the product of 108 x 374. Now, we can add the partial products. Next, we multiply 108 x 3. These are the partial products to add together. This part of the product is 432. The first step in solving this problem is to multiply 108 x 4.

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