Cogito
Grade 4 Math · Chapter 4 · Lesson 3
Multiples
Counting on from a number.
10 problems · about 13 minutes · 4.OA.B.4
What this lesson teaches
The child lists multiples of a number and tells factors and multiples apart.
- A multiple is what you get by multiplying.
- Factors are never bigger; multiples are never smaller.
- A common multiple appears in both lists.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsReview — Prime and Composite: Is 29 prime?
Answer Yes.
Why 29 has only 1 and 29 as factors.
Review — Factor Pairs: How many factors does 36 have?
Answer 9
Why 36 has 9 factors, because 6 × 6 counts only once.
Warm Up
Straightforward practice. Get the method working first.
4 problemsSmallest common multiple of 4 and 10?
Answer 20
Why 20 appears in both lists.
Which is never bigger than the number itself?
Answer A factor.
Why Factors are at most the number. Multiples are at least it.
What is the 5th multiple of 7?
Answer 35
Why 5 × 7.
Is 45 a multiple of 9?
Answer Yes. 9 × 5 = 45.
Why Count in nines.
Build It Up
The same ideas with more to keep track of.
2 problemsSmallest common multiple of 3 and 5?
Answer 15
Why 3, 6, 9, 12, 15.
Can a multiple of 8 be smaller than 8?
Answer No.
Why Multiples count upward.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsThe Buses: One bus comes every 4 minutes, another every 6. After how many minutes do both come together?
Answer 12 minutes
Why 12 is a multiple of both 4 and 6.
The Packs: Buns come in 8s and sausages in 6s. What is the smallest number that matches?
Answer 24 each
Why 24 is the smallest common multiple.