Standard

Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

Student Language:

• "I can find 10 more or 10 less in my head."

Explanation

About the Math, Learning Targets, and Rigor

Resources

Videos

• Khan Academy
  • Scroll to 1.NBT.5, click on skill, find videos on left side of each skill

Extra Practice

• North Carolina Tasks
• Illustrative Math Tasks
• Howard County Tasks
  • Click on 1st grade at bottom, then 1.NBT.5
• Common Core Sheets