# 1.5 Adding Within 100

## Unit Goals

- Students use place value understanding and properties of operations to add within 100.

### Section A Goals

- Add within 100 without composing a ten.
- Use equations to represent addition methods.

### Section B Goals

- Add a one-digit and a two-digit number within 100 with composing a ten.
- Use equations to represent addition methods.

### Section C Goals

- Add 2 two-digit numbers within 100, with composing a ten.
- Use equations to represent addition methods.

### Glossary Entries

**category**A label that tells how objects in a group are alike.**data**Information about the things or people in a group.

Example: If you have a box of colored pencils, then the lengths and colors of each of the pencils are data about the pencils in the box.**difference**The result when one number is subtracted from another.**estimate**To find a value that is close to the correct value.

**greater than**63 is greater than 32.

63 > 32**less than**32 is less than 63.

32 < 63**sum**The total when two or more numbers are added.**survey**A way to collect data using a group of people answering the same question.**teen number**A number with 1 ten and between 1 and 9 ones.

Example:

Fifteen is 1 ten and 5 ones.**two-digit number**