|
Squaring Numbers
Multiplying Numbers
Dividing Numbers
Adding Numbers
- even numbers 2 through selected 2-digit evens
- digits of square of repeating ones
- consecutive odds
- consecutive between 2 numbers
- sequence from 1 to selected 2-digit number
- sequence from 1 to selected 1-digit 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 3-digit 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 the digits of the square of repeating ones
- Square a repeating ones number (111, 11111, etc.).
- Add the digits of the square.
Example:
- If the number selected is 1111:
- Square the number: 1111 × 1111 = 1234321
- Add the digits of the square:
1 + 2 + 3 + 4 + 3 + 2 + 1 = 16
- The answer is the square of the number of ones in 1111.
See the pattern?
- If the number selected is 111111:
- Square the number: 111111 × 111111 = 12345654321
- Add the digits of the square:
1 + 2 + 3 + 4 + 5 + 6 + 5 + 4 + 3 + 2 + 1 = 36
- The answer is the square of the number of ones in 111111.
|
BEATCALC: Beat
the Calculator!
The Math Forum is a research and educational enterprise of the Goodwin College of Professional Studies.