GRE Math : Decimals
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Example Questions
Example Question #1 : How To Convert Decimals To Scientific Notation
Write 
We want to move the decimal point to the place just after the first non-zero number, in this case 6, and then drop all of the non-significant zeros. We need to move the decimal point five spaces to the right, so our exponent should be negative. If the decimal had moved left, we would have had a positive exponent.
In this case we get 6.009 * 10–5.
Example Question #1 : How To Convert Decimals To Scientific Notation
We need to convert 
The trick is, however, figuring out what 
Therefore, for our value, 
Example Question #2 : How To Convert Decimals To Scientific Notation
The easiest way to do this is to convert each of your answer choices into scientific notion and compare it to 
For each of the answer choices, this would give us:
When you convert, you add for each place that you move to the left and subtract for each place you move to the right. (Note that this is opposite of what you do when you multiply out the answer. We are thinking in "reverse" because we are converting.)
Example Question #1 : How To Add Decimals
Solve for 
To add decimals, simply treat them like you would any other number. Any time two of the digits in a particular place (i.e. tenths, hundredths, thousandths) add up to more than ten, you have to carry the one to the next greatest column. Therefore:
So 
Example Question #1 : Decimals
Solve for 
To solve this problem, subtract 
Therefore, 
If you're having trouble subtracting the decimal, mutliply both numbers by 
Example Question #3 : Decimals
Solve for 
To solve, first add 
Then add the decimals together:
Example Question #4 : Decimals
Solve for 
To solve, you need to do some algebra:
Isolate x by adding the 4.150 to both sides of the equation.
Then add the decimals. If you have trouble adding decimals, an effective method is to place one decimal over the other, and add the digits one at a time. Remember to carry every time the digits in a given place add up to more than 
Example Question #5 : Decimals
Solve for 
To solve for 
Then, add your decimals, and remember that 
Example Question #1 : Decimals
Solve for 
To solve, first add 
Then add the decimals together:
Example Question #1 : Decimal Operations
Quantity A:
Quantity B:
The relationship cannot be determined.
The two quantities are equal.
Quantity B is greater.
Quantity A is greater.
The relationship cannot be determined.
Use the values of .5 and 2 as possible x values. If x = 2, Quantity A is positive and greater, but if x = .5, Quantity A is negative and therefore smaller. As such, the relationship cannot be determined.
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