1. Multiplication
Pages

2. Basic Multiplication Facts
Pages
Basic Multiplication Facts
Parts of a Multiplication Problem
82 multiplicand (also called a factor)
x 3 multiplier (also called a factor)
246 product

3. The Multiplication Table
Page 65
The Multiplication Table
It is very important to know the multiplication table.
If you do not know it, take the time to memorize it. The time you spend memorizing the table now will be saved later on because you will be able to do long multiplication & division problems quickly.
any number multiplied by 0 is 0.

4. Multiplying by One-Digit Numbers
Page 66
Multiplying by One-Digit Numbers
Multiply each digit in the top number by the bottom number. The answer should be written from right to left, starting with the product of the ones column, then the tens column, & so on.
Checking a multiplication problem:
go over your steps carefully to find any errors you might have made.
divide the answer you got by the bottom number in the problem.

5. Page 66
Example
Multiply & Check
1) 71
x 9
2) 8,011
x 7
639
56077

6. Page 66
Group Work
Multiply & Check 1) 321 2) 700 x 4 x 5 3) 200 4) 110 x 6 x 9 5) 4,201 6) 3,102 x 4 x 3
1284
3500
1200
990
16804
9306

7. Multiplying by Larger Numbers
Pages 67 – 68
Multiplying by Larger Numbers
When you multiply by a 2-digit number, be sure to begin your answer (the first partial product) directly under the ones columns of the numbers being multiplied. Begin the second partial product directly under the tens columns of the numbers being multiplied & the first partial product. Always multiply from right to left.
When multiplying by zero, write the answer 0 directly under the 0 in the problem. Then multiply by the next digit in the bottom number & continue to the left.
Good for pages 8 and 21

8. Example Pages 67 – 68 Multiply & Check 62 x 23 31,212 x 443 1,426
13,826,916

9. Pages 67 – 68
Group Work
Multiply & Check 1) 73 2) 812 3) 43 x 22 x 34 x 31 4) 411 5) 641 6) 10,220 x 80 x 20 x 123
1,606
27,608
1,333
32,880
12,820
1,257,060

10. Multiplying Numbers Written Horizontally
Pages 69 – 70
Multiplying Numbers Written Horizontally
To multiply numbers written horizontally, rewrite the problem vertically with the shorter number on the bottom. Whether you put the shorter number on the top or the bottom, you will get the same answer. However, by putting the shorter number on the bottom, you will have fewer partial products to add.
Three ways to indicate multiplication.
Good for pages 8 and 21

11. Pages 69 – 70
Example
(941)(20) =
713(30) =
18,820
21,390

12. Multiply & Carrying Pages 71 – 73
Carrying in multiplication is very much like carrying in addition. Be sure to multiply first & then add the number being carried. Carrying is sometimes called regrouping or renaming.
Remember: Any number multiplied by 0 is 0, & you must always multiply before you carry.
Good for pages 8 and 21

13. Example Pages 71 – 73 Multiply & Check 17(4) = 738(9) =
Good for pages 8 and 21

14. Group Work Pages 71 – 73 26(59) = 36(27) = 39(42) = 56(83) = 84(38) =
27(73) =
1,534
972
1,638
4,648
3,192
1,971

15. Pages 74 – 75
Multiply by 10, 100, & 1,000
To multiply a number by 10, add a 0 to the right of the number
To multiply a number by 100, add two 0’s to the right of the number
To multiply a number by 1,000, add three 0’s to the right of the number.
Good for pages 8 and 21

16. Example Pages 74 – 75 Multiply 47 x 10 = 1,000 x 499 =
Good for pages 8 and 21

17. Group Work Pages 74 – 75 Multiply 92 x 10 = 261 x 10 = 209 x 100 =
Good for pages 8 and 21

18. Rounding, Estimating, & Using a Calculator
Pages 76 – 78
Rounding, Estimating, & Using a Calculator
Zeros make many multiplication problems easier.
front-end rounding = To estimate an answer to a multiplication problem, try rounding the larger number to the left-most place.
Good for pages 8 and 21

19. Pages 76 – 78
Example
In the following problems, use the rounding to select the correct answer from the choices. Then check.
36(425) =
798(657) =
8,700
642,826
9,600
524,286
15,300
414,346
21,900
382,156
Good for pages 8 and 21

20. Pages 76 – 78
Group Work
Round the larger number in each problem to the nearest thousand & multiply.
2(4,281) =
7(2,963) =
3(6,059) =
7,516(4) =
5(3,772) =
4(5,693) =
Good for pages 8 and 21

21. Applying Your Multiplication Skills
Pages 79 – 83
Applying Your Multiplication Skills
In each problem, pay close attention to the language that tells you to multiply. In most cases, you will be given information about one thing & you will be asked to apply it to several things.
Good for pages 8 and 21