Mental Math (Add/Subtract) (Grades 2-3)


Mentally adding numbers is an important skill.  There are various ways that numbers can be added mentally.

Mental Math (Add/Subtract) Lesson Plan Includes:

  • Full Teacher Guidelines with Creative Teaching Ideas
  • Instructional Content Pages about Understanding Mental Math (Add/Subtract)
  • Hands-on homework activities giving students practice on Mental Math (Add/Subtract)
  • Answer Keys
  • Common Core State Standards
  • Many Additional Links and Resources
  • Built for Grades 2-3 but can be adapted for other grade levels.

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Mental math is an important skill that can be difficult for your students to master.  There are various ways that numbers can be added mentally.  The lesson describes and provides ample opportunity for students to practice mental math methods like chaining numbers, adding in parts, subtract in two parts, and combining place values.

Classroom Procedure:

  1. Begin by explaining to students that understanding how doing math problems in your head can help you not only solve problems faster, but to understand the properties and fluidity of numbers.
  2. While reading the content pages, reinforce strategies and give students additional examples of mental math problems in order to help them practice.  Use the additional resources to enhance understanding.
  3. Introduce the notes on mental math. Have students practice problems.  As they become comfortable with the strategies introduce more difficult problems.  Use the additional resources to enhance understanding.
  4. Have students practice solving problems using the various mental strategies.
  5. Follow Activity page with students. Have students find the matching bottle tops for each problem on their mat.  Bottle tops can be created using discs or actual bottle tops with the answers written in permanent marker.  Groups can be marked with different color stickers in order to create a lasting classroom activity and to differentiate into difficulty levels.
  6. Distribute Practice page. Check and review the students’ responses as a class.
  7. Distribute the Homework page.
  8. In closing, ask students to tell what strategy they used to solve their mental math problems and why.
  9. Allow for responses and discussion.

Common Core State Standards: 


None for Grade 3

Class Sessions (45 minutes): 1 class session

Additional Resources:

Many more teaching resources in Download!

Want more math resources? Check out our other Math Lesson Plans!

Additional information

Grade Level

2nd Grade, 3rd Grade