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

Add a sequence from one to a selected
2digit
number
 Choose a 2digit number.
 Multiply the 2digit number by half the next number, or
Multiply half the 2digit number by the next number.
Example:
 If the 2digit even number selected is 51:
 The next number is 52. Multiply 51 times half of 52.
 51 × 26: (50 × 20) + (50 × 6) + 1 × 26) =
1000 + 300 + 26 = 1326
 So the sum of all numbers from 1 through 51 is 1326.
See the pattern?
 If the 2digit even number selected is 34:
 The next number is 35. Multiply half of 34 × 35.
 17 × 35: (10 × 35) + (7 × 30) + (7 × 5) =
350 + 210 + 35 = 560 + 35 = 595
 So the sum of all numbers from 1 through 34 is 595.
With some multiplication practice you will be able to find these sums of sequential
numbers easily and faster than someone using a calculator!
