|
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
|
 Finding
15 percent of a number
- Choose a 2-digit number.
- Multiply the number by 3.
- Divide by 2.
- Move the decimal point one place to the left.
Example:
- If the number selected is 43:
- Multiply by 3: 3 × 43 = 129
- Divide by 2: 129/2 = 64.5
- Move the decimal point one place to the left: 6.45
- So 15% of 43 = 6.45.
See the pattern?
- If the number selected is 72:
- Multiply by 3: 3 × 72 = 216
- Divide by 2: 216/2 = 108
- Move the decimal point one place to the left: 10.8
- So 15% of 72 = 10.8.
|
BEATCALC: Beat
the Calculator!
The Math Forum is a research and educational enterprise of the Goodwin College of Professional Studies.