2. SLIDE SHOW INSTRUCTIONS This presentation is completely under your control. This lesson will show only one step at a time, to see the next step you must press a key. to see the next step you must press a key. (Actual names written on a key are in green) TO STOP THE SLIDE SHOW: press ‘escape’ (Esc, top left of keyboard) TO MOVE FORWARD: press the “spacebar” or Enter (PageDn, , , also work) TO MOVE BACKWARD: press the  key (PageUp, or  also work)

3. Multiplication Using Repeated Addition

4. MULTIPLICATION Multiplication is a short-cut way to add the same number over and over again. Example: Say you are playing a game where every time a bell rings you earn 3 points. Now what if the bell rings 5 times? = 15 We earn 3 points for each of the 5 rings. So we will add the number 3, five times In multiplication we write this as 3 times 5, or 3 × 5. adding five “3’s” ring 3 +3 ring +3 ring +3 ring +3

5. Multiplication is REPEATED ADDITION: Let’s say we have the following multiplication problem. 2 times 6 2 (6 times) 2 × 6 This tells us which number to add: 2 And how many times to add it: six times Now write this using math symbols and add: 2 + 2 + 2 + 2 + 2 + 2 = 12 Step 1: Rewrite this using the word “times” instead of the symbol “×” Step 2: Move the word “times” to the end of the problem adding six “2’s”

6. Multiplication is REPEATED ADDITION: Let’s try another example 7 times 4 7 (4 times) 7 × 4 This tells us which number to add: 7 And how many times to add it: four times Now write this using math symbols and add: 7 + 7 + 7 + 7 = 28 Step 1: Rewrite this using the word “times” instead of the symbol “×” Step 2: Move the word “times” to the end of the problem adding four “7’s”

7. The order of the numbers can change and you will still get the same answer. Try 2 × 6 and then 6 × 2. 2 times 6 2 (6 times) 2 × 6 Now write this using math symbols and add: 2 + 2 + 2 + 2 + 2 + 2= 12 adding six “2’s” 6 times 2 6 (2 times) 6 × 2 Now write this using math symbols and add: 6 + 6 = 12 adding two “6’s” Step 2: Move the word “times” to the end of the problem Step 1: Rewrite this using “times” instead of “×” So, sometimes switching the order of the numbers gives you a shorter problem to work.

8. One more example 5 times 8 5 (8 times) 5 × 8 This tells us which number to add: 5 And how many times to add it: eight times Now write this using math symbols and add: 5 + 5 + 5 + 5 + 5 + 5 + 5 + 5 = 40 Step 1: Rewrite this using the word “times” instead of the symbol “×” Step 2: Move the word “times” to the end of the problem adding eight “5’s” The more times the number has to be added, the longer it takes to figure out the answer. This is why it’s faster and easier to use a multiplication chart instead of repeated addition.

9. Practice Problems: (Hit enter to see the answers) Multiply the following numbers using repeated addition 1) 6 x 3 5) 5 x 6 2) 5 x 2 6) 3 x 9 3) 11 x 10 7) 4 x 3 4) 2 x 6 8) 11 x 7 Answers: 1) 18 2) 10 3) 110 4) 12 5) 30 6) 27 7) 12 8) 77

10. Multiplication Using the Chart

11. There are two ways to work a multiplication problem. 1.Use a multiplication chart (or memorize the chart) 2.Add the numbers together as we did in the first few examples. X123456789101112 1 123456789101112 2 24681012141618202224 3 369121518212427303336 4 4812162024283236404448 5 51015202530354045505560 6 61218243036424854606672 7 71421283542495463707784 8 81624324048546472808896 9 918273645546372819099108 10 2030405060708090100110120 11 2233445566778899110121132 12 24364860728496108120132144

12. X123456789101112 1 123456789101112 2 24681012141618202224 3 369121518212427303336 4 4812162024283236404448 5 51015202530354045505560 6 61218243036424854606672 7 71421283542495463707784 8 81624324048546472808896 9 918273645546372819099108 10 2030405060708090100110120 11 2233445566778899110121132 12 24364860728496108120132144 How it works: To find 2 x 3 find the 2 on the side and the 3 on top and follow the rows with your fingers to see where they meet. 6

13. X123456789101112 1 123456789101112 2 24681012141618202224 3 369121518212427303336 4 4812162024283236404448 5 51015202530354045505560 6 61218243036424854606672 7 71421283542495463707784 8 81624324048546472808896 9 918273645546372819099108 10 2030405060708090100110120 11 2233445566778899110121132 12 24364860728496108120132144 To find 2 x 3 you could also find the 3 on the side and the 2 on top and see where they meet. You will get the same answer either way. 6

14. X123456789101112 1 123456789101112 2 24681012141618202224 3 369121518212427303336 4 4812162024283236404448 5 51015202530354045505560 6 61218243036424854606672 7 71421283542495463707784 8 81624324048546472808896 9 918273645546372819099108 10 2030405060708090100110120 11 2233445566778899110121132 12 24364860728496108120132144 Try 5 x 8, we’ll point out both ways on the chart. 40

15. X123456789101112 1 123456789101112 2 24681012141618202224 3 369121518212427303336 4 4812162024283236404448 5 51015202530354045505560 6 61218243036424854606672 7 71421283542495463707784 8 81624324048546472808896 9 918273645546372819099108 10 2030405060708090100110120 11 2233445566778899110121132 12 24364860728496108120132144 Try 6 x 11, we’ll point out both ways on the chart. 66

16. We have learned 2 ways of working multiplication problems. Use a multiplication chart (or memorize the chart) Add the numbers together as we did in the first few examples. X123456789101112 1 123456789101112 2 24681012141618202224 3 369121518212427303336 4 4812162024283236404448 5 51015202530354045505560 6 61218243036424854606672 7 71421283542495463707784 8 81624324048546472808896 9 918273645546372819099108 10 2030405060708090100110120 11 2233445566778899110121132 12 24364860728496108120132144

17. Practice Problems: (Hit enter to see the answers) Multiply the following numbers using the multiplication chart 1) 6 x 7 5) 5 x 12 2) 5 x 9 6) 2 x 8 3) 3 x 10 7) 4 x 8 4) 8 x 6 8) 11 x 12 Answers: 1) 42 2) 45 3) 30 4) 48 5) 60 6) 16 7) 32 8) 132 Compare your answers to the practice problems you did before.

18. End of Tutorial Go to www.greenebox.comwww.greenebox.com for more great math tutorials for your home computer Questions? send e-mail to: lgreene1@satx.rr.com lgreene1@satx.rr.com