Idea 9of 21Builds onRepeat, grow or shrink
Say the rule
How do you tell someone a pattern without listing every term?
Today you'll discover
- the three parts of a pattern rule
- how to follow a rule week by week
- when a pattern stops
Think firstSuzie saves up for a game
Which sentence tells someone the whole pattern of Suzie's savings?
Decide first, then press Next. Find the start, the change and the stop.
Three boxes: has $15 now, earns $5 each week, price $52. Then a sentence: starts at $15, goes up by $5 each week, stop at $52 or more. Then a table of weeks 0 to 8 and the money each week, and a graph with the week 8 dot ringed above a dashed price line. The last step asks for Jimmy's rule.
See the whole ideathe big idea and the key word, in one place
The big idea
A pattern rule says where the pattern starts and how it changes each time.
Fill in the blanks
The pattern starts at __, goes up (or down) by __ each __, and I stop when I get to __ or higher.
- Start$15
- Change+$5 a week
- Stop$52 or more
Easy to get wrongThe start and the change are different numbers. Suzie begins with 15 and adds 5 every week; swap them and every week is wrong.
Key word
- pattern rule
- a sentence that says where a pattern starts, how it changes each time, and (if it does) where it stops
Ready to use it?
- Write the pattern rule for a savings story.
- Use a rule to find when the savings are enough.