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Squaring Numbers
- beginning with 1
- beginning with 5
- beginning with 9
- ending in 1
- ending in 2
- ending in 3
- ending in 4
- ending in 5
- ending in 6
- ending in 7
- ending in 8
- ending in 9
- made up of 1's
- made up of 3's
- made up of 6's
- made up of 9's
- in the 20's
- in the 30's
- in the 40's
- in the 50's
- in the 60's
- in the 70's
- in the 80's
- in the 100's
- in the 200's
- in the 300's
- in the 400's
- in the 500's
- in the 600's
- in the 700's
- between 800-810
- in the 900's
- between 1000-1100
- between 2000-2099
- between 3000-3099
- between 4000-4099
- between 5000-5099
- between 6000-6099
- between 7000-7099
- 3's and final 1
- 3's and final 2
- 3's and final 4
- 3's and final 5
- 3's and final 6
- 3's and final 7
- 3's and final 8
- 3's and final 9
- 6's and final 1
- 6's and final 2
- 6's and final 3
- 6's and final 4
- 6's and final 5
- 6's and final 7
- 6's and final 8
- 6's and final 9
- 9's and final 1
- 9's and final 2
- 9's and final 3
- 9's and final 4
- 9's and final 5
- 9's and final 6
- 9's and final 7
- 9's and final 8
- 1 and repeating 3's
- 1 and repeating 6's
- 1 and repeating 9's
- 2 and repeating 3's
- 2 and repeating 6's
- 2 and repeating 9's
- 3 and repeating 6's
- 3 and repeating 9's
- 4 and repeating 3's
- 4 and repeating 6's
- 4 and repeating 9's
- 5 and repeating 3's
- 5 and repeating 6's
- 5 and repeating 9's
- 6 and repeating 3's
- 6 and repeating 9's
- 7 and repeating 3's
- 7 and repeating 6's
- 7 and repeating 9's
- 8 and repeating 3's
- 8 and repeating 9's
- 9 and repeating 3's
- 9 and repeating 6's
- 6-digits repeating
- 2 rep./sq. of 1 digit
Multiplying Numbers
Dividing Numbers
Adding Numbers
Subtracting Numbers
Finding Percents
Calculation
Practice Exercises
Full List
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Squaring a 2-digit number beginning with 1
- Take a 2-digit number beginning with 1.
- Square the second digit
(keep the carry) _ _ X
- Multiply the second digit by 2 and
add the carry (keep the carry) _ X _
- The first digit is one
(plus the carry) X _ _
Example:
- If the number is 16, square the second digit:
6 × 6 = 36 _ _ 6
- Multiply the second digit by 2 and
add the carry: 2 × 6 + 3 = 15 _ 5 _
- The first digit is one plus the carry:
1 + 1 = 2 2 _ _
- So 16 × 16 = 256.
See the pattern?
- For 19 × 19, square the second digit:
9 × 9 = 81 _ _ 1
- Multiply the second digit by 2 and
add the carry: 2 × 9 + 8 = 26 _ 6 _
- The first digit is one plus the carry:
1 + 2 = 3 3 _ _
- So 19 × 19 = 361.
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