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Learn important squares and square roots

Although you do have a square root function on your GRE calculator, you should almost never use it to calculate the square roots. Remember, the test-makers will never ask you to calculate the square root of a chicken :)

Almost all GRE problems that involve square roots in computations can be easily solved without a calculator if you know the squares at least up to 12, and preferably up to 20, including 25 and square roots of 2 and 3:

22 = 4
32 = 9
42 = 16
52 = 25
62 = 36
72 = 49
82 = 64
92 = 81
102 = 100
112 = 121
122 = 144
132 = 169
142 = 196
152 = 225
162 = 256
172 = 289
182 = 324
192 = 361
202 = 400
252 = 625
≈ 1.41
≈ 1.73

So, square roots should require no computations, since you should already know them:

However, if you get a wacky square root, such as , the GRE test-makers will never require you to convert it to a rough decimal. All that is required to be done is just a simplification. So, the final answer on such GRE problem should be . But in case you do need to calculate the wacky square root, you simply have to check which of the squares you know is the closest to the number you're trying to take square root of. This may work much faster than punching all the buttons on you GRE calculator. For example, you need to find Since 32 is somewhere between 25 and 36, you can estimate that must be between and . So, is somewhere between 5 and 6. Albeit, majority of problems can be solved by simplification:

You don't need GRE calculator for exponents

Other problems where GRE calculator will be tempting but may yield really big and awkward numbers or long decimals are questions involving exponents. Most of these problems will be faster and cleaner to solve with rules than with a calculator. Besides, the test-makers love to give you exponents that are too big to calculate on the GRE calculator. Time spent trying to get an answer out of a calculator for such problems will be time wasted. So, whenever you see large exponents added or subtracted, look to factor or learn how to use the basic rules of exponents:

To find a remainder always use GRE calculator

You know that a standard way to find a remainder is to use long division, however on the GRE you don't need to do this – just use on-screen GRE calculator. It is a real relief for problems that involve remainders.

For example, you need to find a remainder of 99 divided by 13. So, first thing what you have to do is to divide 99 by 13 and what you'll get is the whole number and decimal part: 99/13=7.6153846. Then just subtract the whole number part to get the decimal part only which will be less than one: 7.6153846–7=0.6153846. Next you need to multiply this by the original number you divided by: 0.6153846×13=8. What you'll get is the remainder you are looking for. Try this problem:

Dealing with fractions depends

When you see fractions in answer choices, then the calculator-generated decimal answer may not be very helpful. However, those students who are uncomfortable adding, subtracting, multiplying, or dividing fractions may be tempted to convert all fractions to decimals using GRE calculator. Don’t do it, you are better off mastering fractions than avoiding them:

However, if you need to compare fractions that can't be easily cracked, then just use the calculator and compare the decimals:

Final Point

However, the main criteria that determines whether you should use GRE calculator or not, depends from your arithmetic skills, meaning do you feel you can manage to do simple computations without calculator taking into account the pressure you will be under to complete the exam within the alloted time? Only by practicing under realistic conditions you will learn when you should use GRE calculator and when you should use your brain, because inappropriate use of calculator can significantly slow you down. Try out our GRE simulator for FREE and gain experience you need to achieve the highest possible score.

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