Roots, Exponents, Decimals, Ratios & Percents Flashcards
Square Root of 2
≈ 1.4
Square Root of 3
≈ 1.7
Square Root of 5
≈ 2.25
Square Root of 6
≈ 2.4
Square Root of 7
≈ 2.6
Square Root of 8
≈ 2.8
1/xa
= x-a
1/x-a
= xa
x2< x < x1/2
if…
0 < x < 1
“x is a proper fraction”
If the base is < -1
&
base(+)even int.
** -22 **
The resulting # is….
> the base.
** (+)4
If the base is < -1
&
base(+)odd int.
** -23**
The resulting # is…
< the base
** -8 **
If the base is (+) proper fraction
&
base(+) evenint.
** 1/42**
The result is…
< the base
** 1/16 **
If the base is (-) proper fraction
&
base(+) <strong><em>odd</em></strong> int.
** (-1/3)3**
The result is…
> the base
** ( -1/27) > (-1/3) **
If the base > 1
&
base(+) <b><i>proper fraction</i></b>
** (16)1/2**
The result is…
< the base
** 4 < 16 **
If the base is (+) proper fraction
&
base(+) <b><i>proper fraction</i></b>
** (1/4)1/2**
The result is…
> the base
** ( 1/2 > (-1/4) **
Square root of perfect square scaled to a large number with an EVEN # of “0’s”
=
a # with exactly half the # of zeros to the right of the final non-zero digit as the perfect square.
= 9,000

Cubed root of perfect cube scaled to a large number
=

has 1/3rd the number of zeroes to the right of the final nonxero digit as the perfect cube in question
Squaring Decimals w/ Zeroes
(0.00005)2 = ?
Double the amount of decimal places NOT just the zeroes.
- So…*
(0. 00005)2 has a total of 5 decimals places to the right of decimal point - Therefore…*
The result should have 2x5 (10) decimals places to the right of the decimal point. THIS INCLUDES THE ACTUAL SQUARED #
ANSWER =
.0000000025
(10 total decimal places to the right of the decimal point)
Xn+ Xn=
Xn+1
Remember that there has to be a pair of numbers of the same base raised to the same exponent.
“Decrease of 20%” … “Increase of 25%”
Back to original #.
No % change.
1/6
16.67%
(16%)
5/6
=
0.83
or
83%
1/100
=
0.01
or
1%
3/8
=
.375
or
37.5%
1/8
=
.125
or
12.5%
7/8
=
.875
or
87.5%
5/8
(hint: 1/2 + 1/8)
=
.50 + .125 ► .625
or
50% + 12.5% ► 62.5%
“X varies inversely with Y”
X = k/Y
“X varies directly with Y”
X = kY
- If* x:y and z:x….
- then* what is x:y:z?
find the LCM of the common variable (x) to produce a 3-part ratio
(generally works)
Percent Increase
Final Value = Initial Value ( 1 + “percent greater than”/100)
Percent Less Than
Final Value = Initial Value (1 - “percent less than”/100)

Percent Change
[(Final Value - Initital Value)/Initital Value} x 100
Profit
= (Purchase Price) x (Purchase Percentage)
Selling Price
= (Profit) + (Purchase Price)
112
= 121
132
= 169
142
= 196
152
= 225
43
= 64
53
= 125
63
= 216
73
= 343
83
= 512
93
= 729
103
= 1000
00
= 1 or undefined
28
= 256
24
= 16
25
= 32
26
= 64
27
= 128
33
= 27
34
= 81
43
= 64
44
= 256