Ch. 7 Simplify: Cross-Cancelling Fractions

What does cross-cancelling mean when multiplying fractions?

• Reducing diagonally using common factors

• Finding prime factors of all numbers

• Converting to mixed numbers first

• Adding numerators before multiplying

Tags

CCSS.5.NF.B.6

Before multiplying 2/4 × 8/12, which diagonal pair has a common factor you can cancel?

• 4 and 8 share factor 5

• 2 and 12 share factor 2

• 2 and 8 share factor 3

• 4 and 12 share factor 7

Tags

CCSS.5.NF.B.6

Compute 2/4 × 8/12 using cross-cancelling to simplify first.

(a)  

Tags

CCSS.5.NF.B.6

Which step is correct when cross-cancelling 5/24 × 2/17?

• Cancel 5 with 17 using factor 5

• Cancel 2 with 17 using factor 2

• Cancel 5 with 24 using factor 1

• Cancel 2 with 24 using factor 2

Tags

CCSS.7.NS.A.2A

Find the product: 5/24 × 2/17. Simplify your answer.

(a)  

Tags

CCSS.5.NF.B.6

True or False: Cross-cancelling uses the Greatest Common Factor diagonally across the multiplication.

• False

• True

Choose all expressions that correctly show a cross-cancel step for 2/5 × 8/30.

• Cancel 2 with 8 by 2

• Cancel 5 with 8 by 5

• Cancel 5 with 30 by 5

• Cancel 2 with 30 by 2

Tags

CCSS.7.NS.A.2A

Compute 2/5 × 8/30 by cross-cancelling first. Give the simplified product.

(a)  

Tags

CCSS.5.NF.B.6

Which mistake is common when students try to cross-cancel?

• Reducing before multiplying

• Simplifying the final product

• Cancelling diagonally with GCF

• Cancelling numbers on the same fraction

Tags

CCSS.5.NF.B.6

Find the product: 8/9 × 7/13. Simplify your answer.

(a)  

Tags

CCSS.5.NF.B.6