Common Denominator Fraction Problems

LCM is helpful when (2 answers)

• reducing a fraction to its simplest form

• finding a common denominator to compare fractions

• finding a common denominator to add/subtract fractions

• reducing a mixed fraction to improper

Check off everything you need to do before adding/ subtracting fractions:

• find the gcf of all fractions

• find the LCM of all denominators

• find the LCM of all numerators

• make whole numbers over 1

Check all fraction operations that required common denominators:

• addition

• subtraction

• multiplication

• division

• comparing fractions

• Change Mixed numbers into improper fractions.

• Get common denominators and equivalent fractions.

• Follow Adding Rules across the top and keep the same denominator.

• All of the above.

When the denominators are not the same, I must find a...

• common numerator

• common denominator

• equivalent fraction

• mixed number

When adding or subtracting fractions, I NEVER add or subtract the...

• numerators

• denominators

• mixed numbers

• equivalent fractions

Is this a correct answer?

• Yes, the student correctly added.

• No, you cannot add unlike denominators

• No, 5 + 7 is not 12

• No, 2 + 3 is not 5

What is the first step in solving this problem? 
⅘ + ½ =

• Add the top parts of the fraction

• Rewrite the fractions in the simplest form. 

• Find a common denominator. 

• Make each fraction into an improper faction. 

The number one rule for adding and subtracting fractions is to...

• find the GCF.

• find a least common denominator.

• line up the fractions.

• add the numerators.

3/8 + 4/8 =

• 7/8

• 7/16

• 9/8

• 1/8