General Math Strategies

Question 1

How to square a number ending in 5

Answer 1

1. Remove 5 from digits
2. Add 1 to the remaining digit/s
3. N • (N+1) = ?
4. Add 25 after finding product above

Question 2

Why not use calculator

Answer 2

1. Slow

2. Simplify through logic by estimation needed more than precise calculation

Question 3

Estimate: “What is 26.3% of $7,935?

Answer 3

1. Round 26.3% to 25%, which is also ¼
2. Round 7935 to 8000
3. A fourth of 8000 is 2000
4. So pick an answer closest to 2000

Question 4

When dividing large number by 5…

Answer 4

Double N, then divide by 10, or vise-versa, whichever is easier

Question 5

What logic of dividing-by-five suggest

Answer 5

The related logic of doubling and halving

Question 6

Apply doubling-and-halving trick to: 16 * 35 = N

Answer 6

1. Half 16 so that it is reduced to 8
2. Double 35 so that it becomes 70
3. 8 * 7 = 56
4. Add 0 after 56
5. 560

Question 7

When to use doubling-and-halving

Answer 7

When multiplying two large numbers

Question 8

Essence of QC questions

Answer 8

Comparing two quantities to see which is bigger

Question 9

What are the four standard choices for every Quantitative Comparison GRE math questions?

Answer 9

1. Quantity A is greater
2. Quantity B is greater
3. The two quantities are equal
4. The relationship cannot be determined from the information given

Question 10

What fourth standard QC answer choice mean

Answer 10

That variables within specified ranges allow for different results

Question 11

3 essential QC facts

Answer 11

1. Answers evenly distributed between four standard choices
2. 7-9 QC questions
3. Easy ones take than 45 sec to answer; harder ones less than 2 min

Question 12

Best QC trick

Answer 12

Calculate only to APPROXIMATE answer

Question 13

2 QC tricks to remember

Answer 13

1. Part-wise

2. Rounding

Question 14

QC matching operations trick to simplify problem

Answer 14

1. • same # to both quantities
2. • same # from both quantities
3. • or / both quantities by same positive #