7th grade math rules

KEEP(the first number), CHANGE(the - to +), CHANGE(number to its opposite)

• multiply fractions

• divide fractions

• solve proportions

• subtract negative

top x top then bottom x bottom

• add/subtract fractions

• multiply fractions

• divide fractions

• order of operations

1)keep the first fraction, 2) change x to division, 3) get the reciprocal(FLIP) of the second fraction

• divide fractions

• multiply fractions

• add/subtract negatives

• distributive property

always positive, distance a number is from 0

• multiply negatives

• circumference

• absolute value

• divide fractions

1) denominator x whole number, 2) add the numerator, 3) keep your answer over the same denominator

• absolute value

• mixed number to improper fraction

• multiply fractions

• fraction to decimal

Set up fraction bar, =, fraction bar, 1)cross multiply, 2) divide by what’s left

• solve proportions

• unit rate

• multiply fractions

• divide fractions

To find the total(cost - discount) 1)start with 100 and SUBTRACT the percent 2)multiply the percent x the number

• percent change

• gratuity

• discount

• markup

PxRxT    $ x % x Years

*Sometimes you will need to add your answer back to the “$” if the question wants you to find the TOTAL.

• percent of a number

• solve proportion

• percent change

• simple interest

1)subtract 2)divide by the original

• simple interest

• percent change

• discount

• commission

To find the total: 1)start with 100 and add the percent 2)multiply the percent x the number

• commission

• percent change

• percent of a number

• tip,markup,tax