This document provides instructions for multiplying by 10 and 11. It explains that to multiply by 10, one adds a zero to the end of the number. Multiplying by 11 involves doubling the last digit for numbers under 9. For numbers over 9, one adds the digits and places the sum between them. Examples are provided to demonstrate these techniques.

1. http://math.pppst.com/banner_math_m
ultiplication.gif
Multiplication
Multiplying by 10 and 11

2. Multiplying by 10
Multiplying by 10 is EASY! http://www.pv
.noacsc.org/Po
rtals/0/H.%20
All you do is add a zero on the end! Bockrath/math
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t.gif

3. http://www.youtube.com/watch?v=jPO5zAwfRSc

4. Do you see the pattern?
0
10
20
30
40
50
60
70
80
90
0 10 20 30 40 50 60 70 80 90 100
http://www.jeremynoeljohnson.com/jimages/blogposts/blanktimestable01.png

5. Now you try it…
10 x 4 = ? 10 x 9 = ?
40 90
10 x 7 =? 10 x 6 = ?
70 60

6. Multiplying by 11
Numbers less than 9—All you do is double
the digit to get the product.
So… 11 x 5 = 55
11 x 7 = 77
What does 11 x 8 = ?
88
http://sekolahcikal.files
.wordpress.com/2009/1
2/funmath.jpg

7. What’s the pattern here?
11
22
33
44
55
66
77
88
99
http://www.jeremynoeljohnson.com/jimage
s/blogposts/blanktimestable01.png

8. What do you do for numbers
greater than 9?
http://www.youtube.com/watch?v=QMPDLQ71PI8

9. Multiplying Numbers Greater Than 9
11 x 26 = ?
If you take 2+6 you get 8.
Put the 8 between the 2 and the 6 to get your
answer.
11 x 26 = 286
http://www.cfsnc.org/uploaded/News_and_Events/i
mages/Lower_School/math_clip_art_01.jpg

10. Now you try it…
11 x 23 = ? 11 x 18 = ?
253 198
11 x 32 = ? 11 x 12 = ?
352 132

11. Mixed Review
11 x 35 = ? 11 x 5 = ?
385 55
10 x 9 = ? 10 x 2 = ?
90 20
10 x 4 = ? 11 x 8 = ?
40 88

12. Works Cited
Handley, B. "Speed Math for Kids: The Fast, Fun Way to Do Basic
Calculations." ERIC: Reports. U.S. Department of Education, 2007.
Educators Reference Complete. Web. 11 Oct. 2011.
Pierce, R. (18 Feb 2011). "Multiplication - Times Tables." Retrieved from
http://www.mathsisfun.com/tables.html
Rak Productions. (September, 1999). Multiplication Song (multiply by
10). Retrieved from http://www.youtube.com/watch?v=jPO5zAwfRSc
Rak Productions. (September, 1999). 11 Times Trick (for numbers
greater than 9)-Multiplication Math Song. Retrieved from
http://www.youtube.com/watch?v=QMPDLQ71PI8
Su, Francis E. (1999) Multiplication by 11. Retrieved from
http://www.math.hmc.edu/funfacts