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Squaring Numbers
Multiplying Numbers
Dividing Numbers
- any by 0.125
- 2 digits by 1 1/9
- 2 digits by 1 1/8
- 2 digits by 1 1/7
- 2 digits by 1 1/6
- 2 digits by 1 1/5
- 2 digits by 1 1/4
- 2 digits by 1 2/7
- 2 digits by 1 1/3
- 2 digits by 1 2/5
- 2 digits by 1 3/7
- 2 digits by 1 1/2
- 2 digits by 1 3/5
- 2 digits by 1 2/3
- 2 digits by 1 3/4
- 2 digits by 1 4/5
- 2 digits by 2 2/9
- 2 digits by 2 1/4
- 2 digits by 2 1/3
- 2,3 digits by 2 1/2
- 2 digits by 2 2/3
- 2 digits by 2 6/7
- 2 digits by 3 1/8
- 2,3 digits by 3 1/3
- 2 digits by 3 1/2
- 2 digits by 3 4/7
- 2 digits by 4 1/6
- 2 digits by 4 2/7
- 2 digits by 4 4/9
- 2 digits by 4 1/2
- 2 digits by 5
- 2 digits by 5 5/7
- 2 digits by 6 1/4
- 2 digits by 6 2/3
- 2 digits by 7 1/7
- 2 digits by 7 1/2
- 2 digits by 8 1/3
- 2 digits by 8 4/7
- 2 digits by 12 1/2
- 2 digits by 15
- 2,3 digits by 16 2/3
- 2,3 digits by 25
- 2,3 digits by 33 1/3
- 2,3 digits by 35
- 2 digits by 37 1/2
- 2 digits by 40
- 2 digits by 45
- 2 digits by 50
- 2 digits by 62 1/2
- 2 digits by 66 2/3
- 2,3 digits by 75
- 2 digits by 83 1/3
- 2 digits by 87 1/2
- 2 digits by 125
- 2 digits by 166 2/3
- 2 digits by 250
- 2,3 digits by 333 1/3
- 2 digits by 375
- 2 digits by 625
- 2 digits by 875
- 3 digits rep./37+41
- 6 digits rep. by 15873
- 6 digits rep. by 7, then 13
- 6 digits rep. by 13, then 11
- 6 digits rep. by 7,11,13, subtract 101
- 6 digits rep. by 37037 x 5
- mixed numbers by 2
- diff. of squares of 2 consec. 2-digit numbers
- diff. of squares of 2 different 2-digit numbers
- sqrt of squares of 2-digit numbers ending in 1
- sqrt of perfect squares ending in 5
Adding Numbers
Subtracting Numbers
Finding Percents
Calculation
Practice Exercises
Full List
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Dividing a 2- or 3-digit number by 33 1/3
- Select a 2-digit number (progress to larger ones).
- Multiply it by 3.
- Move the decimal point 2 places to the left.
Example:
- The 2-digit number chosen to divide by 33 1/3 is 46.
- Multiply by 3: 3 × 46 = 3(40 + 6) = 120 + 18 = 138
- Move the decimal point 2 places to the left: 1.38
- So 46 divided by 33 1/3 = 1.38.
(If you divide by 33.3 using a calculator, you will not get the exact answer.)
See the pattern?
- If the 3-digit number chosen to divide by 33 1/3 is 650:
- Multiply by 3: 3 × (600 + 50) = 1800 + 150 = 1950
- Move the decimal point 2 places to the left: 19.50
- So 650 divided by 33 1/3 = 19.5.
Practice multiplying left to right and this procedure will become an easy one
- and you will get exact answers, too.
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