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

Adding
a series of ten numbers
 Have a friend choose and write down a singledigit number. (Two digits for experts.)
 Ask your friend to name and note a third number by adding the first two.
 Name a fourth by adding the second and third. Continue in this way, announcing
each number, through ten numbers.
 Ask your friend to add up the ten numbers. You will give the answer before he
or she can finish:
The sum of all the terms of this series will be the seventh number multiplied
by 11.
Example:
 If the numbers selected are 7 and 4:
 The series jotted down is: 4, 7, 11, 18, 29, 47, 76, 123, 199, 322.
 The seventh number is 76. 11 × 76 = 836
(use the shortcut for 11: 7 is the first digit, 6 is the third digit;
the middle digit will be 7 + 6, and carry the 1: 836).
 So the sum of the ten numbers is 836.
