Mathematics (2019) Grade(s): 2

MA19.2.13

Mentally add and subtract 10 or 100 to a given number between 100 and 900.

Unpacked Content

Knowledge

Students know:
  • use place value models for adding and subtracting numbers from 1 to 1000.
  • use strategies for mentally adding and subtracting multiples of 10 and 100.

Skills

Students are able to:
  • use patterns and regularity in counting sequences and understandings of place value to add or subtract a "ten" or a "hundred".
  • communicate reasoning and solution strategies.

Understanding

Students understand that:
  • the digits of a 3-digit number represent amounts of hundreds, tens and ones.
  • patterns in the place value system can be used to mentally compute sums and differences.
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