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

Finding
55 percent of a number
 Choose a 2digit number.
 Multiply the number by 11. (Add digits from right to left  see examples).
 Divide by 2.
 Move the decimal point one place to the left.
Example:
 If the number selected is 81:
 Multiply by 11: 11 × 81 = 891
right digit is 1
next digit to left is 1 + 8 = 9
last digit to left is 8
 Divide by 2: 891/2 = 445.5
 Move the decimal point one place to the left: 44.55
 So 55% of 81 = 44.55.
See the pattern?
 If the number selected is 59:
 Multiply by 11: 11 × 59 = 649
right digit is 9
next digit to left is 9 + 5 = 14 (use the 4 and carry 1)
last digit to left is 5 + 1 = 6
 Divide by 2: 649/2 = 324.5
 Move the decimal point one place to the left: 32.45
 So 55% of 59 = 32.45.
