The WHY's of fractions

When adding or subtracting fractions, why must the fractions first be written in equivalent forms that all have the same denominator?

• We must have the same number of parts to find the size.

• We can only add or subtract parts of the same size.

• Adding with different denominators would reduce the parts.

• We can only add or subtract if the sizes and the number of parts match.

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

Which Properties of Real Numbers allow us the write a fraction as an equivalent fraction?

• Multiplicative Inverse and Multiplicative Associative

• Multiplicative Associative and Multiplicative Commutative

• Multiplicative Identity and Multiplicative Commutative

• Multiplicative Identity and Multiplicative Inverse

Tags

CCSS.3.OA.B.5

In order to multiply fractions,

• the numerators must be the same

• the denominators must be the same

• one numerator must be the same as one denominator

• it is not necessary for anything to be the same

Tags

CCSS.5.NF.B.6

To write a fraction as an equivalent fraction we

• multiply the fraction by a fractional form of one

• multiply the fraction by the reciprocal

• add the same number to both the numerator and the denominator

• subtract the same number from both the numerator and the denominator

Tags

CCSS.3.NF.A.3A

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

Which answer is incorrect.

When multiplying fractions, the denominators do not have to match because

• When we multiply the denominators together they will necessarily change, hence, there is no need for them to be the same.

• Multiplying fractions is finding a multiple or a portion of one of the fractions.

• Multiplication is a higher order operation than addition or subtraction.

• We have to multiply to get an equivalent fraction. If the denominators had to match to multiply, then we would not be able to multiply to get equivalent fractions with a common denominator.

Tags

CCSS.3.NF.A.1

CCSS.3.NF.A.2B

Select the incorrect statement.

Reduction of a fraction ...

• is done by dividing out forms of one.

• works because anything times a form of one is a form of itself.

• is allowed by a combination of the multiplicative identity property and the multiplicative inverse property.

• works because the multiplicative inverse property allows us to subtract the same factor from the numerator and denominator.

Tags

CCSS.3.NF.A.3A

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

Subtraction is

• multiplication by the reciprocal

• addition of the opposite

• multiplication of the opposite

• addition of the reciprocal

Tags

CCSS.7.NS.A.1B

Division is

• addition of the opposite.

• addition of the reciprocal.

• multiplication by the opposite.

• multiplication by the reciprocal.

Tags

CCSS.7.NS.A.2A