Cogito
Grade 4 Math · Chapter 4 · Lesson 4
Number Patterns
Follow the rule, then notice what it did not say.
10 problems · about 15 minutes · 4.OA.C.5
What this lesson teaches
The child generates a number pattern from a rule and describes a feature the rule did not state.
- A rule builds a pattern one step at a time.
- The pattern often has features the rule never mentioned.
- Say why the feature happens, not just that it does.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsReview — Multiples: Smallest common multiple of 4 and 10?
Answer 20
Why 20 appears in both lists.
Review — Prime and Composite: Is 29 prime?
Answer Yes.
Why 29 has only 1 and 29 as factors.
Warm Up
Straightforward practice. Get the method working first.
4 problemsStart at 7, add 4. What is the 5th term?
Answer 23
Why Four steps of 4 from 7 gives 23.
Why does "start at 3, add 4" keep every term odd?
Answer Adding an even number keeps it odd.
Why An odd number plus an even number is always odd.
Start at 3, add 5. What is the 4th term?
Answer 18
Why 3, 8, 13, 18.
Start at 100, subtract 7. What is the 3rd term?
Answer 86
Why 100, 93, 86.
Build It Up
The same ideas with more to keep track of.
2 problemsStart at 1, double each time. What is the 5th term?
Answer 16
Why 1, 2, 4, 8, 16.
Start at 4 and add 10. Are the terms all even?
Answer Yes. Even plus even stays even.
Why 4, 14, 24, 34.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsThe Chairs: Each table seats 4, plus 2 at the ends. With 5 tables, how many seats?
Answer 22 seats
Why 20 + 2 = 22 seats.
The Savings: Ana starts with 5 pounds and adds 3 each week. How much after 6 weeks?
Answer 23 pounds
Why 5 + 18 = 23 pounds.