SSAT math kids
How many odd integers are there between 1 and 9
3
irrational number
radical that can't be simplified, or a non-repeating, non-terminating decimal
parallel lines
same slope
imaginary number
square root of a negative number i= √-1
converse of the Pythagorean theorem
a²+b²=c²
rhombus
parallelogram with all sides congruent
part, percent, whole formula
part=percent/100× whole
Slope-intercept form of a line
y = m x + b
slope intercept form
y=mx+b m=slope=Rise/run b=y intercept=where the line crosses y axis
√x *(√y)
√xy
midpoint formula
((x₁+x₂)/2,(y₁+y₂)/2)
sum of all interior angles in a polygon
(n-2)180 n=number of sides
slope between two points
(y₂-y₁)/(x₂-x₁)=rise/run
0.1/ 0.02 =
.1/.02 = 10/2= 5
16% of 10% of 500 =
.16 × .1 × 500= .16 × 50 = 8
16% of what number is 25% of 80?
.16 × x = .25 × 80 .16x = 20 x = 20/.16 = 2000/16 = 125
60% of what percent of 500 is equal to 6?
.6 × x × 500 = 6 300x = 6; x= 6/300 = 2/100 = 0.2 2%
1/4 equals what decimal?
0.25
25 % equals what fraction and decimal 75 % equals what fraction and decimal
0.25 and 1/4 0.75 and 3/4
x⁰
1 (anything to the 0 power is 1)
what to do for each question
1. Annotate/read carefully 2. Write the formula 3. show your work 4. make sure you answered the question
10 % equals what fraction and decimal 20% equals what fraction and decimal 70% equals what fraction and decimal
1/10 and 0.1 2/10 and 0.2 7/10 and 0.7
area of a trapezoid
1/2(b₁+b₂)h
volume of a pyramid
1/3 * base area * height
A restaurant sells 100 hamburgers a day at $10 each. To increase business, they reduce the price to $8 before noon. If they sell 40 hamburgers before noon, how many will they have to sell after noon to keep their hamburger revenue the same?
100 × $10 = $1000 (daily burger revenue) 40 × $8 = $320 (revenue from $8 burgers) $1000 - $320 = $680 = revenue from $10 burgers $680/$10 = number of $10 burgers they have to sell 68
List the first five multiples of 11
11, 22, 33, 44, 55
The average weight of 4 girls is 110. The average weight of 3 boys is 125. What is the average weight of all 7 children rounded to the nearest pound?
110 × 4 = 440; 125 × 3 = 375 440+375 = 815; 815 ÷ 7 ≅ 116
1/8 equals what percent and decimal
12.5 % and 0.125
Area of Parallelogram
A = b * h
1 pound (lb) = ? ounces
16 ounces (oz)
A student answered 75% of the questions on a test correctly and left 7% of the questions blank. What percentage of the questions did the student answer incorrectly?
18%
What is the sum of the angles in a triangle?
180°
1 quart (qt) = ? pints
2 pints (pts)
2/5 - 3/4 =
2/5 - 3/4 = 8/20 - 15/20 = -7/20
What is the largest of 7 consecutive numbers if the average is 17?
20
What Percent of 32 is 24?
24 = x × 32 x = 24/32 = 3/4 = .75 = 75%
pythagorean triples
3, 4, 5/ 5, 12, 13/ 7, 24, 25 (plus every multiple of them)
π = what fraction and what decimal
3.14 or 22/7
.6 = what fraction
3/5
1/3 equals what percent and decimal
33 1/3 % and 0.33333..
If there are the same number of tricycles as bicycles at school, and the total number of wheels is 30, how many bicycles are there?
3x + 2x = 30 5x = 30; x = 6 6 bicycles and 6 tricycles
1 gallon = ? quarts
4 quarts (qts)
What is the sum of the angles in a rectangle
4 right angles = 4 × 90 = 360°
Area of Triangle
A = ½ b h
Area of Circle
A = πr²
distance between two points
d=√[(x₂-x₁)²+(y₂-y₁)²] (pythagorean theorem)
5/0 vs. 0/5
5/0 is undefined and 0/5 is 0
What is the length of the diagonal of a square whose side is 5 inches?
5√2 inches
180/ 0.03 =
6000
2/3 equals what percent and decimal
66 2/3 % and 0.666667
What is the ten-digit in the number 182.09?
8
What is the hundredth digit in the number 182.09?
9
How many factors does 100 have?
9 and they are 1, 2, 4, 5, 10, 20, 25, 50, 100
What is a 3-4-5 Right Triangle?
A right triangle with legs of lengths 3 and 4; hypotenuse of length 5
What is 3² × 3⁵
Add exponents in multiplication 3⁷
Circumference of a Circle
C = π d or C = 2 π r
If 3(x+y) = 21 Then what does x + y =?
Divide both sides by 3 7
percent change
difference/original× 100%
triangle inequality
Given a triangle with sides a, b, and c difference < c < sum a-b < c < a+b
45-45-90 Right Triangle (or half of a square)
Hypotenuse is equal to length of the side times √2.
How much money does Bob have after 2 years if he started with $500 and the interest rate is 6%?
Interest = 500 × .06 = $30/year $30 × 2 years = $60 Total = $500 + $60 = $560
Sides of a triangle
Longest side must be shorter than the sum of the other two sides
Adding and subtracting radicals
Need to have like terms. Can only add and subtract radicals with the same radical.
Is 2 a multiple of 8?
No, it is a factor
If r+s+t= 40 and s−7=20, what is the value of r?
Not enough information! 3 variables, and only 2 equations The most you know is that (r+t) = 13
If Sam lives 6 miles from school, and Peter lives 3 miles from school, how far apart do they live?
Not enough information! If Sam and Peter live in the same direction, it is 3 miles; if they live on opposite sides of the school, it is 9 miles, or it could be any distance in between.
average speed
distance/time
420/ (5 X 12 + 10) =
Remember PEMDAS! 420/(70) = 6; [NOT 420/(5 ×22)] 6
What is the slope of the line containing the points (4,2) and (2,1)?
Slope = change in y divided by change in x = (2-1)/(4-2) = ½ OR = (1-2)/(2-4) = -1/-2 = ½
integers
numbers that don't have fraction or decimal -2, -3, 0, 2, 3
What is 2¹⁰ ÷ 2⁶
Subtract exponents in division 2⁴ = 16
What are supplementary angles?
They add to 180°
Which is greater: 5/9 or 6/11?
Use criss-cross method 5×11 = 55; 6×9 = 54; therefore 5/9 > 6/11
rational numbers
a number that can be written as a fraction, repeating decimal, or terminating decimal
What is the sum of the angles in an octagon?
add 180° every time you add a side (start with triangle) 180 + 180 + 180 + 180 + 180 + 180 OR (n-2)×180 = (8-2)×180 = 6×180 = 1080°
what is the sum of the angles in a pentagon?
add 180° every time you add a side (start with triangle) 180 + 180 + 180 OR (n-2)×180 = (5-2)×180 = 3×180 540°
vendiagram questions
add up all the number--difference between the sum and total is both--then calculate how many only have one or have both
regular polygon
all angles and sides are the same
real number
anything that can be put on a number line
circle
area:πr² circumference:2πr
standard form
ax+by=c
volume of a prism
base area * height
surface area of a pyramid
base area + 1/2 * p * l p = perimeter of base l = slant height
12 + 2x > 24 - x What does x =
combine like terms: 3x > 12 x > 4
perpendicular lines
negative reciprocal 1/2 and -2/1
The slopes of perpendicular lines are _______________
negative reciprocals (Examples: 3 and -1/3; 1/2 and -2; 3/4 and -4/3; -2/5 and 5/2)
Is 1 a prime number?
no
whole numbers
numbers 0 or greater that don't have a fraction or decimal 0, 1, 2, 3...
exterior angles
sum of all exterior angles is 360 interior+exterior=180
A number is divisible by 4 if
the last 2 digits are divisible by 4
Parallel lines have ___________ slope
the same
A number is divisible by 3 if
the sum of the digits is divisible by 3
x intercept
where the line crosses the x axis plug in 0 for y and solve for x
y intercept
where the line crosses y axis plug in 0 for x and solve for y
45, 45, 90 right triangle
x, x, x√2
30, 60, 90 right triangle
x, x√3, 2x
exponent rules: x⁵/x²
x³ (subtract the exponents)
exponent rules: (xy²)³
x³y⁶ (multiply the exponents)
exponent rules: x²*x³
x⁵ (add the exponents)