## Reflection: Intervention and Extension Sequences as Functions (Part 1 of 2) - Section 2: New Info

Triangular numbers have many interesting properties. For example, a triangular number sequence can never end with the digits 2, 4, 7, or 9.

I like to ask my students if they can find any other interesting properties of the triangular numbers. One possible answer is that triangular numbers are either divisible by 3 or have a remainder of 1 when divided by 9. This can be an open question that students can complete in class today, or over the next few days.

More about Triangular Numbers
Intervention and Extension: More about Triangular Numbers

# Sequences as Functions (Part 1 of 2)

Unit 7: Functions
Lesson 10 of 11

## Big Idea: Sequences can be thought of as functions with their own special qualities that are obvious on a graph.

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Standards:
Subject(s):
Math, Graphing (Algebra), formulas, function, sequences
55 minutes

### Mauricio Beltre

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