Rational numbers Can be fractions, decimals, negatives, etc.
Integers Negatives or positive whole numbers, but can’t have fractions or decimals
Multiplying and Dividing Integers Triangle rule
Adding Integers Same sign, add and keep. Different sign subtract. Keep the sign of the higher number, then you’ll be exact.
Subtracting Integers Insert plus sign after first number. Or use plus plus rule.
Solving for x Add or subtract from both sides. Divide by number in front of x.
Inequalities Flip sign when dividing or multiplying both sides by a negative.
Unit Rate Divide
Unit Price Money in the bank $ Amt.
Discounts Change it to a decimal and multiply. Read the problem to see if you need the total price. If so, then subtract.
Change it to a decimal and multiply % Change it to a decimal and multiply
Tax, tip, markup, commission Change it to a decimal and multiply. Read the problem to see if you need to total price. If so, add.
Percent increase or decrease Subtract, put answer on top. Original on the bottom. Divide and move your decimal for percent of change. (song)
Scale drawing, map scale or model
Based on this data (these results)
Converting Measurements
Ratio
3 numbers and 1 unknown (comparing two items or rates)
Missing sides of Similar Figures
-Congruent angles Proportional sides Similar Figures -Congruent angles Proportional sides
Simple Interest I = Prt Principal x rate x time
Compound Interest A = P (1 + r) t Principal (1 + rate as decimal) raised to the years power No calculator: need to make a table
Constant of proportionality y x
Fraction times fraction Probability of 2 events Fraction times fraction (Pay attention to whether you replace it or not)
Predictions from probability
Circumference C = d C = 2 r C Revolution or the turning of a wheel, tire, etc. . . . Anything circular Circumference C = d C = 2 r
Circumference Diameter We use 3 and find the answer a little bit higher
Adjacent Angles Side by side Share one side in the middle
Vertical Angles Across from each other Congruent
Supplementary Add up to 180o Straight line
Complementary Add up to 90o Corners
Missing angle of a triangle Add up. Subtract from 180
Shape inside a shape Find the area of both and subtract
Shape combined with another shape Find the area of both and add
B Area of base (must use formula)
Area Cover, carpet, or paint . . . Answer choices are in units2 or square units Area
Pour, fill, units3 Volume
Find area of each face and base. Add together. Total Surface Area Find area of each face and base. Add together.
Find area of each face (sides not bases). Add together. Lateral Surface Area Find area of each face (sides not bases). Add together.
Net Worth Add up income, money you earn, etc. Add up bills, money you owe, etc. Subtract the two totals.