Unit Plan 5 (Grade 1 Math): True/False Equations & Unknowns
Determine true/false equations and find unknowns within 20 in Grade 1 using models, make-10, and count-on/back strategies to reason about “= as the same value as.”
Focus: Determine if equations are true/false and find missing numbers to make equations true, using clear models and explanations.
Grade Level: 1
Subject Area: Mathematics (Operations & Algebraic Thinking)
Total Unit Duration: 5 sessions (one week), 45–60 minutes per session
I. Introduction
Students internalize that the equal sign (=) means “the same value as.” They test and repair equations, justify true/false decisions with models, and solve for the unknown in all positions (e.g., □ + 7 = 13, 12 = □ + 5, 15 – □ = 8). Emphasis is on reasoning, not guess-and-check.
Essential Questions
- What does the equal sign really mean in an equation?
- How can a model (e.g., ten-frame, number line, tape (bar) diagram) show that two sides have the same value?
- How do I find the unknown number and prove my answer is correct?
II. Objectives and Standards
Learning Objectives — Students will be able to:
- Decide whether an equation is true or false and explain why using models and numbers.
- Determine the unknown that makes an equation true (within 20), in any position.
- Use facts, make-10, and count-on/back strategies to solve and verify.
- Critique and improve mathematical statements using precise math language.
Standards Alignment — CCSS Grade 1 (threaded across the unit)
- 1.OA.7: Understand the equal sign; determine if equations are true or false.
- 1.OA.8: Determine the unknown number in an equation.
- Mathematical Practices: MP.3 (construct arguments/critique) emphasized; MP.1–MP.2, MP.4, MP.6–MP.8 threaded.
Success Criteria — Student Language
- I can tell if an equation is true or false and show why.
- I can find the unknown number that makes an equation true.
- I can use a model and math words to convince a partner my work is correct.