### Examples

*Example:*The difference 612-17 can be found by rewriting it as 612-12-5 which is equivalent to 600-5 which is equivalent to 595.

*Example:* The difference 1,000-17 can be found by using a number line and making a “jump” of 10 from 1,000 to 990 and then 7 “jumps” of 1 to 983.

### Clarifications

*Clarification 1:*Instruction includes the use of manipulatives, number lines, drawings or properties of operations or place value.

*Clarification 2: *Instruction focuses on composing and decomposing ones, tens and hundreds when needed.

**Subject Area:**Mathematics (B.E.S.T.)

**Grade:**2

**Strand:**Number Sense and Operations

**Date Adopted or Revised:**08/20

**Status:**State Board Approved

## Related Courses

## Related Access Points

## Related Resources

## Formative Assessments

## Lesson Plan

## STEM Lessons - Model Eliciting Activity

This MEA asks students to decide which factors are important in choosing the best cookie in a cookie contest. Students will take on the role of cookie critics to provide feedback to a teacher whose grade level is deciding which cookie to use for a fundraiser. They will rank order their choices from the best to worst cookie. Students will provide a detailed written explanation for how they decided to rank factors and their solution. They will show their work while adding up to 4 two-digit numbers to calculate the total number of votes.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom.

## MFAS Formative Assessments

Student are asked to consider why a counting strategy works to solve subtraction problems.

Students are asked to explain each step of an addition problem completed by using the standard algorithm.

Students are asked to explain each step of a subtraction problem completed by using the standard algorithm.

Students explain another student's written strategy for adding and written strategy for subtracting three-digit numbers.