6. multiplying 2 to 4-digit numbers by multiplies of 10
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This document discusses multiplying numbers by multiples of 10. It provides examples of multiplying 2-4 digit numbers by multiples of 10. The key points are: - To multiply by a multiple of 10, multiply the non-zero digits first and then add the appropriate number of zeros to the end based on the multiple of 10. - The number of zeros in the product will equal the number of zeros in the multiplying factor. - Examples are provided of word problems involving multiplying amounts by multiples of 10 to find totals, along with step-by-step workings. Practice problems and assignments are also included.
6. multiplying 2 to 4-digit numbers by multiplies of 10
- 1. Multiplying 2-to 4-Digit Numbers by Multiplies of 10
- 2. Find the product. a)21 b) 122 c) 3 012 x 5 x 6 x 4 d) 4 024 e) 313 x 2 x 3
- 3. In a toy factory, a group of workers filled the 21 boxes with 50 toy cars each. How many toy cars were filled in the boxes?
- 4. What is asked? ( the total number of toy cars that were filled in all the boxes) What are the given facts? ( 21 boxes and 50 toy cars ) What shall we do find the answer? ( multiply ) What is the number sentence for the problem? (21 x 50 = N)
- 5. Step 1 21 x 50 00 Step 2 21 x 50 00 105 Step 3 21 x 50 00 105 1050 ( 1 050 toy cars were filled in all boxes )
- 6. 0 10 20 30 40 50 60 70 80 90 100 110 120 130 How many zeros are there in 12 tens? How many zeros are there in 10? What did you do with zero? 12 x 10 or 12 x 10 = 120 120
- 7. a. To multiply by a multiple of 10, multiply the non-zero digits first, and then annex zeros in the product. b. The number of zero in the factors is equal to the number of zeros in the product.
- 8. Solve the following problems: 1. There are 165 trays of oranges. Each tray has 20 oranges. How many are there in all? 2. Grade 3 SPED A class has 43 pupil. Each pupil has 10 books each. How many books did they have altogether? 3. If there are 24 bottles in a case, how many bottles will there be in 30 cases?
- 9. Exercise: 1) 36 x 10 2) 25 x 20 3) 45 x 30 4) 232 x 20 5) 9 201 x 30 a. 36 a. 2 520 a. 1 350 a. 2 320 a. 276 030 b. 360 b. 2 500 b. 1 530 b. 6 420 b. 270 603 c. 3 610 c. 500 c. 1 340 c. 4 640 c. 273 060
- 10. Assignment: A.Answer the following: 1) 73 x 10 = 2) 25 x 30 = 3) 15 x 10 = 4) 62 x 10 ( <,>,= ) 60 x 10 5) 43 x 20 ( <,>,= ) 53 x 10
- 11. B. Find the product: 1)77 x 10 = 2)250 x 20 = 3)2 248 x 20 = 4)1 623 x 30 = 5)4 132 x 40 =