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Subtracting Fractions. By: Greg Stark EC&I 831. Subtracting Fractions. As with adding, before fractions may be subtracted from one another, the pieces of the whole, the denominator, must be the same size. - PowerPoint PPT Presentation

Subtracting FractionsBy: Greg StarkEC&I 831

Subtracting FractionsNumerator--------------------DenominatorRepresents the number of parts into which the whole has been divided Represents the number of partsof a whole we have.As with adding, before fractions may be subtracted from one another, the pieces of the whole, the denominator, must be the same sizeFractions with the same denominator are called like fractions and can be subtracted from each other

Subtracting Like Fractions-To subtract like fractions, subtract the numerators from each other in order and place the difference (answer) over the original denominator

==

Subtracting Like FractionsAnother example:

-== 4---- 4=

Subtracting fractions from a whole56-In order to subtract a fraction from a whole, we need to regroup one of the wholes (or borrow)

Look at the denominator of the fraction that is being subtracted in this case, 12ths

This will be what we regroup the whole into so we will have like fractions5

Subtracting fractions from a wholeAnother example:

34-In order to subtract a fraction from a whole, we need to regroup one of the wholes (or borrow)

Look at the denominator of the fraction that is being subtracted in this case, 3rds

This will be what we regroup the whole into so we will have like fractions3

Subtracting unlike fractions-As with adding, before fractions may be subtracted from one another, the pieces of the whole, the denominator, must be the same size

The denominators of the fractions do not match we must find the LCM of 4 and 6 and make equivalent like fractions, before we subtract

=-=X 3----X 3X 2----X 2

Subtracting unlike fractions-As with adding, before fractions may be subtracted from one another, the pieces of the whole, the denominator, must be the same size

The denominators of the fractions do not match we must find the LCM of 3 and 5 and make equivalent like fractions, before we subtract

=-=X 5----X 5X 3----X 3

Review: to subtract fractionsIf the fractions are not like fractions, convert them to equivalent like fractionsIf you have no fraction, or too little of a fraction to subtract from, regroup one whole into the desired number of pieces (the denominator) and add them to the numeratorSubtract the numerators from each other in order and place the difference over the original denominatorReduce the resulting fraction to lowest termsChange improper fractions to mixed numbers