What Else Do You Notice?

Find things about a pattern that the rule doesn't say.

Warm-up, learn, try it together, practice, then a quick check. About 15 minutes.

What children learn in Level 42

Patterns show things the rule doesn't say. Rule: start at 3, add 4. The terms are 3, 7, 11, 15, 19.
Look: every term is odd! The rule never said that. Why does it keep happening?
It starts odd, and adding 4, an even number, to an odd number always makes an odd number. So it stays odd forever.
If the rule adds an odd number, like 5, the terms switch: odd, even, odd, even. Start at 2, add 5: 2, 7, 12, 17.

Georgia's K-12 Mathematics Standards:

4.PAR.3.1 — Generate both number and shape patterns that follow a provided rule.