Math Flashcards
absolute value
of units/distance a number is from 0 on number line
absolute value symbol: | |
|-3|= 3
adding integers w/ the same sign
add numbers together & keep the sign
7 + 4 = 11 -2+-3= -5
adding integers w/ different signs
subtract numbers & keep the sign of the larger number
-7 + 2 = -5
changing subtraction to addition
-8-(-7)
change subtraction sign outside parentheses to positive change sign of # inside parentheses to its opposite
-8-(-7) = -8+(7) = -1
subtracting integers
3 - (-10)
change subtraction sign to plus 3 + (-10)
change sign of # following subtraction sign to opposite 3+10
rounding
4 - = down
5+ = up
When multiplying integers w/ the same sign, answer will be + or - ?
positive
9 x 12 = 108
-7 x -5 = 35
When multiplying integers w/ different signs, answer will be + or - ?
negative
-8 (9) = -72
When dividing integers w/ different signs, answer will be + or - ?
negative
-63 / 9 = -7
When dividing integers w/ the same sign, answer will be + or - ?
positive
-7 ÷ -5 = 35
24 ÷ 12 = 2
PEMDAS
Please Excuse My Dear Aunt Sally
Parentheses Exponents Multiplication
Division Addition Subtraction ( left to right)
perimeter
outside measurement of flat surfaces
add sides together
Find the perimeter of a square postage stamp if one side is 22mm.
P = 4s
P = 4(22)
P = 88 mm
How can you find the perimeter of a square?
side + side + side + side
P = 4 side
P = 4s
How can you find the perimeter of a rectangle?
length + length + width + width
P = 2(length) + 2(width)
P = 2L + 2W