click below
click below
Normal Size Small Size show me how
7th math fromulas
2011-2012 7th grade math formulas
Question | Answer |
---|---|
% proportion | is/of=%/100 |
% of change propportion | change/original=%/100 |
sales tax | 1.original price tax% (as a decimal) =tax amt. 2. total amt.= original price + tax amt |
tip | 1.original price tax% (as a decimal) =tax amt. 2. total amt.= original price + tax amt |
discount | 1.original price x discount%(as a decimal)=discount amt 2.total =original price |
simple interest | interest= principal x rate x time(i=prt) |
area of a rectangle | area=(base x height) |
area of a triangle | area=(base x height)/2 |
area of a trapezoid | area=(height(base 1+base2))/2 |
area of a circle | area= pi x radius^2 |
circumference of a circle | circumference= 2 x pi |