Practice Set · Part 1
Find Factors and Multiples
Pick up where we left off
Where we left off
Our goal: With my small group, I can find the greatest common factor and the least common multiple of two numbers, and use each to solve a real problem — one step at a time, with support.
The big idea: GCF = the biggest number that divides BOTH — use it to split into equal groups. LCM = the smallest number BOTH divide into — use it to find when cycles meet again.
Model to copy — Watch me build the combo packs
- The store has 48 pencils and 36 notebooks. Every combo pack must hold the same number of each, with nothing left over — so the number of packs has to be a factor of BOTH quantities.
- Factors of 48: 1, 2, 3, 4, 6, 8, 12, 16, 24, 48. Factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36. Listing them in order is what makes the comparison easy.
- The numbers in both lists are the common factors: 1, 2, 3, 4, 6, and 12.
- The greatest of those is 12, so the GCF of 48 and 36 is 12. The manager can make 12 combo packs — each holding 48 ÷ 12 = 4 pencils and 36 ÷ 12 = 3 notebooks.
Start here
You did these with your group. Now do them on your own — the model above is yours to copy.
- 1
Same stepsFinish what the group started. Use the model above, step for step.
Let's do one together — the same GCF, using prime factors: A factor tree breaks each number into primes. 48 = 2 × 2 × 2 × 2 × 3, and 36 = 2 × 2 × 3 × 3. Now look at what the two share: two 2s and one 3. Multiply the shared primes: 2 × 2 × 3 = 12. Same answer as the lists, 12 — which is the check. For big numbers, the factor tree is usually the faster road.My first step is ___ , because the problem asks for ___ .
Show your work - 2
Warm restartWhich expression is equivalent to 5x + 2x?
- A7x
- B10x
- C7x²
- D52x
- 3
Warm restartAre 3(n + 2) and 3n + 6 equivalent? Test with n = 4.
- AYes — both equal 18
- BNo — one is 18 and one is 14
- CYes, but only when n = 0
- DYou cannot test with a number
- 4
Warm restartSimplify 6a + 4 − 2a.
- A4a + 4
- B8a
- C2a + 4
- D4a
Practice Set · Part 2
Find Factors and Multiples
Keep going
You answered these out loud. Now write them.
Answer, then say how you know — the reason is the part that counts.
- 5
Think it throughWhat is the GCF of 48 and 36?
- A12
- B6
- C144
- D4
Why is that the answer?
I chose ___ because ___ .
- 6
Think it throughWhat is the LCM of 6 and 8?
- A24
- B48
- C2
- D14
How do you know?
I chose ___ because ___ .
- 7
Think it throughA problem asks when two repeating schedules meet again. Which do you use?
- AThe least common multiple
- BThe greatest common factor
- CEither one works
- DNeither — you list factors
Explain your thinking.
I chose ___ because ___ .
- 8
Back to the modelBoth problems say “common.” How do you decide whether a problem wants the GCF or the LCM?
If the problem ___ something into equal groups, I use the ___. If it asks when things ___ again, I use the ___.
Sort it again — on paper this time
Write the letter of the group each one belongs in.
- What is the largest number of identical combo packs?
- When will both classes fall in the same week again?
- How many equal groups can I split both stocks into?
- Hot dogs come in 10s and buns in 8s — when do they match?
- The answer is never bigger than either number
- The answer is never smaller than either number
Practice Set · Part 3
Find Factors and Multiples
Words and reasoning
Word bank · Banco de palabras
Use the words
Fill each blank with a word from the bank.
- Factors ___ a number; multiples are what it ___.
- A number that divides another exactly, with no remainder, is a ___.
- What you land on counting by a number are its ___.
- The largest number that divides both is their ___ ___ ___.
Explain the thinking
- 9
Find the mistakeAnother student made this exact mistake in this lesson. Explain why it is wrong, then write what they should have done.
The mistake: A common mistake is reaching for the wrong tool: listing FACTORS for a problem about repeating cycles. - 10
Say moreHow did you find the factors that 24 and 36 share, and how did you decide which one is the GCF?
The common factors are ___.
- 11
Change one numberGo back to Part 1 and pick one problem you already solved. Change one number in it, then solve your new version. Show every step.
If ___ changed to ___ , then ___ .
Show your work
Practice Set · Part 4
Find Factors and Multiples
Show what you know
Last check
These two come from Lesson 6.6. If they are shaky, that is the lesson to revisit — not this one.
- 12
Show what you knowQuick check — you've got this: Two supply runs repeat every 6 weeks and every 8 weeks, and both happen this week. When will they next happen in the same week?
- AWeek 24, the least common multiple of 6 and 8
- BWeek 2, the greatest common factor of 6 and 8
- CWeek 48, because 6 × 8 = 48
- DWeek 14, because 6 + 8 = 14
Explain your choice.
I know it is ___ because ___ .
- 13
From Lesson 6.6Quick check — you've got this: Which expression is equivalent to 6n + 4 + 3n − 1?
- A9n + 3
- B9n + 5
- C63n
- D18n + 4
- 14
From Lesson 6.6Test it: what does each expression equal when h = 5?
- ABoth equal 60
- BBoth equal 90
- CA = 60 and B = 55
- DA = 50 and B = 60
Be honest — this tells your teacher what to do next
| I can… | Not yet | Getting there | Got it |
|---|---|---|---|
| I can find the greatest common factor and the least common multiple of two numbers, and use each to solve a real problem — one step at a time, with support. | |||
| I can explain why it works: GCF = the biggest number that divides BOTH — use it to split into equal groups… | |||
| I can talk through each step out loud using a sentence frame and the lesson's key words. |
One question I want to ask my group next time