Grade 7 · Math · Unit 2 of 20
Factors & Exponents
GCF, LCM and powers
What your child practises
Finding the greatest common factor and lowest common multiple, and writing and evaluating repeated multiplication with exponents.
Ontario Curriculum expectation: B2.6, B2.7 · greatest common factor, lowest common multiple and exponential notation
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
What is the lowest common multiple of 3, 4 and 6?
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12
Hint: Find a number that all three divide into evenly. Check the smallest.
Question 2
Ribbons 36 cm and 60 cm long are cut into equal pieces with none left over. What is the longest each piece can be, in centimetres?
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12
Hint: This is the greatest common factor of the two lengths.
Question 3
What is the greatest common factor (GCF) of 72 and 32?
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8
Hint: List the factors of each number. Find the biggest one they share.
Question 4
What is the lowest common multiple (LCM) of 10 and 2?
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10
Hint: List the multiples of each number. Find the smallest one they share.
Question 5
What is the greatest common factor (GCF) of 10 and 6?
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2
Hint: List the factors of each number. Find the biggest one they share.
Question 6
Which shows 2 × 2 × 2 × 2 using an exponent?
- 2 × 4
- 4²
- 2⁴
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2⁴
Hint: The base is the number being multiplied. The exponent counts how many times it appears.