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 800810
 in the 900's
 between 10001100
 between 20002099
 between 30003099
 between 40004099
 between 50005099
 between 60006099
 between 70007099
 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
 6digits repeating
 2 rep./sq. of 1 digit
Multiplying Numbers
Dividing Numbers
Adding Numbers
Subtracting Numbers
Finding Percents
Calculation
Practice Exercises
Full List

Squaring numbers in the 400s
 Choose a number in the 400s (keep the numbers low at first;
then progress to larger ones).
 The first two digits of the square are 16: 1 6 _ _ _ _
 The next two digits will be 8 times the last 2 digits: _ _ X X _ _
 The last two places will be the square of the last two digits: _ _ _ _ X X
Example:
 If the number to be squared is 407:
 The first two digits are 16: 1 6 _ _ _ _
 The next two digits are 8 times the last 2 digits:
8 × 7 = 56: _ _ 5 6 _ _
 Square the last digit: 7 × 7 = 49: _ _ _ 4 9
 So 407 × 407 = 165,649.
For larger numbers reverse the steps:
 Square the last two digits (keep the carry):
_ _ _ _ X X
 8 times the last two digits + carry: _ _ X X _ _
 16 + carry: X X _ _ _ _
See the pattern?
 If the number to be squared is 425:
 Square the last two digits (keep the carry):
25 × 25 = 625 (keep 6): _ _ _ _ 2 5
 8 times the last two digits + carry:
8 × 25 = 200; 200 + 6 = 206 (keep 2): _ _ 0 6 _ _
 16 + carry: 16 + 2 = 18: 1 8 _ _ _ _
 So 425 × 425 = 180,625.
