Factor 10 + 15 using its GCF. Make the inside numbers relatively prime.
5(2 + 3)
GCF = 5; 10 = 5 × 2 and 15 = 5 × 3.
Day 013Factoring Sums
Standards 6.NS.B.4c
LEARNING TARGET
I can factor a sum using the greatest common factor.
01 · LEARN
Build the idea
Find the GCF of the two addends. Divide each addend by that factor and place the quotients inside parentheses. The inside numbers should share no common factor greater than 1.
Factor 18 + 30 using its GCF. Make the inside numbers relatively prime.
6(3 + 5)
GCF = 6; 18 = 6 × 3 and 30 = 6 × 5.
02 · PRACTICE
Your turn
Work in order. Start with the foundations, then build toward explanation and application.
Factor 6 + 9 using its GCF. Make the inside numbers relatively prime.
Factor 8 + 12 using its GCF. Make the inside numbers relatively prime.
Factor 10 + 15 using its GCF. Make the inside numbers relatively prime.
Factor 18 + 30 using its GCF. Make the inside numbers relatively prime.
Factor 45 + 60 using its GCF. Make the inside numbers relatively prime.
Factor 12 + 18 using its GCF. Make the inside numbers relatively prime.
Factor 48 + 72 using its GCF. Make the inside numbers relatively prime.
Factor 24 + 36 using its GCF. Make the inside numbers relatively prime.
Factor 60 + 84 using its GCF. Make the inside numbers relatively prime.
Factor 70 + 100 using its GCF. Make the inside numbers relatively prime.
03 · CHECK
Answers and reasoning
Reveal the teacher answer key
- 3(2 + 3)
GCF = 3; 6 = 3 × 2 and 9 = 3 × 3.
- 4(2 + 3)
GCF = 4; 8 = 4 × 2 and 12 = 4 × 3.
- 5(2 + 3)
GCF = 5; 10 = 5 × 2 and 15 = 5 × 3.
- 6(3 + 5)
GCF = 6; 18 = 6 × 3 and 30 = 6 × 5.
- 15(3 + 4)
GCF = 15; 45 = 15 × 3 and 60 = 15 × 4.
- 6(2 + 3)
GCF = 6; 12 = 6 × 2 and 18 = 6 × 3.
- 24(2 + 3)
GCF = 24; 48 = 24 × 2 and 72 = 24 × 3.
- 12(2 + 3)
GCF = 12; 24 = 12 × 2 and 36 = 12 × 3.
- 12(5 + 7)
GCF = 12; 60 = 12 × 5 and 84 = 12 × 7.
- 10(7 + 10)
GCF = 10; 70 = 10 × 7 and 100 = 10 × 10.