Basic Arthimetic Flashcards
1/6 =
.166
What does the square root of 3 equal approximately?
A little more than 1.5
.166=
1/6
5/6=
.833
.833=
5/6
1/8=
.125
.125
1/8
3/8=
.375
.375=
3/8
5/8=
.625
.625=
5/8
7/8=
.875
.875=
7/8
12x12
144
144
12x12
12x11
132
132
12x11
120
12x10
12x10
120
108
12x9
12x9
108
12x8
96
96
12x8
84
12x7
12x7
84
72
12x6
12x6
72
12x5
60
60
12x5
12x4
48
48
12x4
36
3x12
3x12
36
11^2
121
Sq root of 121
11
12 squared
144
Sq root 144
12
Sq root 169
13
13 squared
169
14 squared
196
Sq root 196
14
15 squared
225
Sq root 225
15
Perfect squares 10 to 15
100, 121, 144, 169, 196, 225
13x3
39
39/13
3
13x4
52
52/13
4
52/4
13
13x5
65
13x6
78
13x7
91
13x8
104
117/13
9
11x10
110
110/11
10
11x12
132
132/11
12
132/12
11
143/13
11
143/13
11
11x13
143
12x13
156
156/13
12
Multiples of 1/9 appear as…
1/9=.111 2/9=.222 6/9=.666
Divisible by 2
Even
Divisible by 3?
Digits add to a number divisible by 3
Divisible by 4?
Last two digits are divisible by 4
Divisible by 5?
Ends in 0 or 5
Divisible by 6
Divisible by 2 (even) and divisible by 3(all digits add to a number divisible by 3)
Divisible by 9?
All digits add to a number divisible by 9
Divisible by 10
Ends in zero
Do the following produce integers?
Int + Int
Int - Int
Int)(Int
(Int)/(Int)
Integers plus or minus integers always equal integers. Integers multiplied by integers always produce integers. Integers divided by integers do not necessarily produce integers.
What is a prime number?
It’s divisible only by 1 and itself
Is 0 prime?
No
Is 1 prime?
No
Are negatives prime?
No
What is the smallest prime number?
2
What are the even prime numbers?
2
What are linear equations?
Can be mapped on a coordinate grid. No exponents
If you have n variables, how many distinct equations do you need to solve for the all the variables ?
N equations. Make sure that the equations are distinct and not just multiples of one another
How do you solve multiple linear equations?
Substitution or combination. Most often you’ll need to use combination.
What are traps on linear equations?
Radicals that indicate both positive and negative roots.
Describe the steps to solve a linear equation
Radicals Eliminate denominators Move all terms to one side Combine like terms Factor if necessary Divide if necessary
What are equations?
Anything with an equal sign. If it’s a word problem the word “is” often denotes and equal sign.
What are inequalities?
The solve for a range of values.
How do you sole inequalities?
Same as equations but if you multiple or divide by a negative number you reverse the sign. Do not multiple or divide by a variable if you’re unsure if it’s positive or negative.
What combinations of decimals will appear in 1/7?
.142857 repeating
X % written as a fraction is?
X/100
Percent literally means:
Per 100
Part/whole x 100 describes what?
A percent.
X% of y =
Y% of X
X% of Y=
(X/100)(Y)
Any number ending in x multiplied by another number ending in x will produce a number ending in x. What numbers is this true for?
0, 1, 5, 6,
GMAT tests what numbers?
Real numbers! No i / imaginary numbers tested on the exam
What is the strategy for unusual number property problems?
Start doing something with smaller versions of the number set and look for patterns. EX: if it asks for a pattern in the units digit just focus on that and not the big number.
Does (even)/(even) produce an even?
Sometimes yes/sometimes no. There are no universal odd/even divisibility rules. Ex: 12/2=6. 12/4=3.
What are integers?
Whole numbers.
Do integers include negatives?
Yes
Do integers include 0?
Yes
What are digits?
Numbers/Symbols 0 –> 9
How many digits are there?
- 0–>9
Why does distinct mean?
Only appears once
Is zero positive or negative?
Neither!
Is zero even or odd?
Even
Is zero an integer?
Yes
Is zero a multiple?
Yes, if every number
Is zero prime?
No
Describe the digits placement of 284.374
Hundredths/tenths/units.tens/hundredths/thousandths
(Odd)(odd)=
ODD
Odd + even
ODD.
What combinations of odd/even produce odd numbers?
Only (odd)(odd) and (odd) +/- (even)
Even x what is even?
Even x anything is EVEN
