Math Review

to calculate the area of a triangle...

1/2 (base x height)

quartile

1/4 of a data set

perpendicular means

a right angle at 90 degrees

to determine the mean...

add all the numbers in the data set and then divide by how many numbers there are, for example: 2, 3, 5, 7, 8 would be 2+3+5+7+8 = 25 and then 25 divided by 2 = 12.5

to calculate the perimeter of a rectangle or square...

add the length of all four sides

when adding and subtracting numbers with decimals...

be sure to line up the decimals vertically, including space values on either side, such as ones, tens, hundreds, tenths, hundredths, etc; then add or subtract as normal, carrying the decimal straight down.

inner quartile range

center 50% of a data set

to reduce a fraction...

divide both the top and bottom numbers by the same number; always reduce your answers

to calculate the area of a trapezoid...

draw lines so that there are only squares, rectangles, or triangles; calculate the area for each shape separately; then add all values together

to add and subtract fractions...

first find a common denominator and then add only the top numbers

gcf

greatest common factor

lcm

least common multiple

to calculate the area of a rectangle or square...

length x width

to calculate the volume of a cube or rectangular prism ...

length x width x height

when multiplying numbers with decimals...

line the numbers up as if there is not decimal present, do the multiplication, then add the decimals at the end (count the total spaces in both numbers)

to determine the mode...

list the numbers in the data set and decide which number occurs most often

to determine the median...

list the numbers in the data set in numerical order and find the number in the middle

to determine the range...

list the numbers of the data set in numerical order and subtract the lowest value from the highest value

when dividing fractions...

multiply by the reciprocol

to multiply fractions...

multiply the top values and then multiply the bottom values

The relationship between sides of a rectangle is that...

opposite sides are equal length

when solving a conversion problem...

set up two equivalent fractions, one with the conversion factor (will usually be given) and the second with the same units on top and bottom as the conversion factor, for example; 12 inches = 1 foot, how many feet in 36 inches.... 12 inches/1 foot = 36 inches / ? feet

when solving a percentage problem...

set up two equivalent fractions, one with the percentage number over 100 and the second with the part over the whole,

recirprocol

when a fraction is flipped upside down

The height of a triangle is found...

where a line is drawn perpendicular to the base.