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.
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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