Squaring Numbers
Multiplying Numbers
Dividing Numbers
Adding Numbers
 even numbers 2 through selected 2digit evens
 digits of square of repeating ones
 consecutive odds
 consecutive between 2 numbers
 sequence from 1 to selected 2digit number
 sequence from 1 to selected 1digit number and back
 sequences in the 10's
 sequences in the 20's
 sequences in the 30's
 sequences in the 40's
 sequences in the 50's
 sequences in the 60's
 sequences in the 70's
 sequences in the 80's
 series of doubles
 series of quadruples
 series of 10 numbers
Subtracting Numbers
 1's repeating, divide by 9, subtract 21
 8's repeating, divide by 9, subtract 10
 squares of two numbers
 reversing/adding/subtracting 3digit numbers
Percents
 finding 2.5 percent
 finding 5 percent
 finding 15 percent
 finding 20 percent
 finding 25 percent
 finding 33 1/3 percent
 finding 40 percent
 finding 45 percent
 finding 55 percent
 finding 60 percent
 finding 70 percent
 finding 75 percent
Calculation
Practice Exercises
Full List

Subtract
from a repeating 8's number, divide
by
9, subtract 10
 Select a number between 2 and 9 digits made up of 8's.
 Subtract a number equal to 9 minus the number of digits in the number you have
selected.
 Divide by 9. The answer will have one less digit than the original number in
the series 98765432.
 Subtract 10.
Example:
 If the repeating number selected has 4 digits: 8888:
 Subtract 5 (9 minus the number of digits) and divide by 9. The answer will be
987 (1 less digit in sequence than the 4 digits in the selected number).
 Subtract 10: 987  10 = 977.
 So (88885) / 9  10 = 977.
See the pattern?
 If the repeating number selected has 6 digits: 888888:
 Subtract 3 (9 minus the number of digits) and divide by 9. The answer will be
98765 (1 less digit in sequence than the 6 digits in the selected number).
 Subtract 10: 98765  10 = 98755.
 So (8888883) / 9  10 = 98755.
Extend this exercise by changing the last number to subtract, producing a multitude
of easily answered problems.
