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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 numbers in the 200s
- Choose a number in the 200s (practice with numbers under 210,
then progress to larger ones).
- The first digit of the square is 4: 4 _ _ _ _
- The next two digits will be 4 times the last 2 digits: _ X X _ _
- The last two places will be the square of the last digit: _ _ _ X X
Example:
- If the number to be squared is 206:
- The first digit is 4: 4 _ _ _ _
- The next two digits are 4 times the last digit:
4 × 6 = 24: _ 2 4 _ _
- Square the last digit: 6 × 6 = 36: _ _ _ 3 6
- So 206 × 206 = 42436.
For larger numbers work right to left:
- Square the last two digits (keep the carry):
_ _ _ X X
- 4 times the last two digits + carry: _ X X _ _
- Square the first digit + carry: X _ _ _ _
See the pattern?
- If the number to be squared is 225:
- Square last two digits (keep carry):
25x25 = 625 (keep 6): _ _ _ 2 5
- 4 times the last two digits + carry:
4x25 = 100; 100+6 = 106 (keep 1): _ 0 6 _ _
- Square the first digit + carry:
2x2 = 4; 4+1 = 5: 5 _ _ _ _
- So 225 × 225 = 50625.
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