Idea 5of 21Builds onFind the missing term
Which shape is 20th?
How do you predict a shape far along a repeating pattern?
Today you'll discover
- where each core ends
- how to jump by whole cores
- how to count into the next core
Think firstTriangle, circle, square, again and again
What is the 20th shape in this pattern?
Decide first, then press Next. Find where each core ends.
A row of shapes, triangle, circle, square, repeated four times, with position numbers 1 to 12 under them and a box for the 20th shape at the far right. Brackets mark each group of three, ending at 3, 6, 9 and 12. Working underneath says 6 whole cores make 18, and 20 minus 18 is 2, the 2nd shape of the next core: a circle.
See the whole ideathe big idea and the key word, in one place
The big idea
To predict a far shape, jump by whole cores, then count into the next one.
Using division20 ÷ 3 is 6 with 2 left over. The left-over 2 says which shape of the core: the 2nd.
Easy to get wrongNothing left over means the LAST shape of the core, not the first: the 18th is a square.
Key word
- position
- a term's place in a pattern: 1st, 2nd, 20th
Ready to use it?
- Predict a far term of a repeating pattern.
- Explain the prediction using the core.