Multiplication Pages 60 - 86

Basic Multiplication Facts Pages 62 - 64 Basic Multiplication Facts Parts of a Multiplication Problem 82 multiplicand (also called a factor) x 3 multiplier (also called a factor) 246 product

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.

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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