Knowledge/Skill Building

🧠 Menu Proof Mini-Lesson

Content Expertise Academic Mindset Critical Thinking & Problem Solving Effective Communication Collaboration CCSS.Math.Content.4.NF.B.4 CCSS.Math.Content.4.NF.C.5 CCSS.Math.Content.4.NBT.B.5 CCSS.Math.Content.4.NBT.B.4 Product Assessment Reflection Core Content Community Partners Critique and Revision Submission Required

The teacher models how to justify a snack serving choice with fraction strips, tenths-to-hundredths grids, arrays, area models, and the standard algorithm. Students practice on one sample menu card by comparing portions with 1/2, rewriting a tenths fraction as hundredths, and checking total servings with multiplication or multi-digit computation. Teams annotate a simple proof frame they will reuse in their prototype boards.

Plan day

Day 6

Duration

35 min

Grouping

Whole Class

Steps

6 steps

Lesson plan

6 steps · 35 min

#	What teachers do
1	[Facilitator] Launch the mini-lesson by showing a sample snack menu card and naming the goal: build a clear math proof that could make sense to a cafeteria staff member. Briefly review proof tools students already know—fraction strips, hundredths grids, arrays, area models, partial products, and the standard algorithm—and tell students they will choose which tools best fit each part of the menu claim. (5 min)
2	[Facilitator] Model one complete proof aloud on chart paper or a document camera. Compare a snack portion to 1/2 with fraction strips, rewrite a tenths fraction as hundredths on a 10x10 grid, and solve a total-serving problem using an array or area model and then connect it to the standard algorithm; include any needed addition or subtraction to check totals and label each step with words, drawings, and equations. (10 min)
3	[Facilitator] Lead a quick guided discussion in which teams identify why each tool was used and which strategy was most convincing for a real audience. Introduce or revisit brief vocabulary such as equivalent fractions, proof, justify, and algorithm, and post sentence starters students can reuse in their own annotations. (5 min)
4	[Facilitator] Give each team one sample menu card and a proof frame. Ask teams to work together to annotate the frame by choosing visuals and equations that show: how the portion compares to 1/2, how tenths can be renamed as hundredths, and how multiplication or multi-digit computation proves the total servings; circulate to prompt revision and check accuracy. (15 min)
5	[Facilitator] Run a partner-to-partner share and quick critique round. Teams read one part of their proof aloud, listen to feedback on clarity and correctness, and revise labels, equations, or visual models so the frame is stronger for later prototype boards. (5 min)
6	[Facilitator] Close with an exit circle. Each student shares one proof strategy they used and one way their team collaborated respectfully, then collect annotated proof frames as a checkpoint for the next activity, Three Snack Menu Sketches. (5 min)

Preparation (9 items)

Create or print one simple sample snack menu card per team that includes a fraction comparison opportunity, a tenths-to-hundredths conversion, and a multiplication or multi-digit total-serving problem.
Prepare a teacher model of the sample proof on chart paper, slides, or a document camera that includes labeled fraction strips, a 10x10 hundredths grid, an array or area model, equations, and a short written justification.
Copy one reusable proof frame per student or team with sections for claim, visual model, equation, explanation, and final check.
Gather materials for each table: fraction strips, colored pencils or crayons, base-ten or grid paper, scratch paper, and pencils.
Post sentence starters such as 'We know this portion is balanced because...', '___/10 is equivalent to ___/100 because...', 'We chose an area model/algorithm because...', and 'Our calculation is correct because...'.
Pre-select 1-2 computation examples that connect area models, partial products, and the standard algorithm so students can see relationships among strategies.
Plan mixed-readiness teams and note which students may need enlarged proof frames, pre-highlighted sections, or oral directions repeated in smaller chunks.
Prepare a simple feedback prompt for the critique round, such as 'Is the visual clear?', 'Does the equation match the model?', and 'Would a cafeteria staff member understand this proof?'.
Set up a collection spot for annotated proof frames so they can be reused during the next menu sketch activity.

Student-facing instructions

You will work with your team to build a clear math proof for one sample snack menu card. You will use tools such as fraction strips, a hundredths grid, arrays, area models, and equations to show how a serving compares to 1/2, how a fraction in tenths can be rewritten in hundredths, and how multiplication or another multi-digit calculation proves the total servings. Your materials are the sample menu card, proof frame, fraction strips, grid paper, pencils, and colored pencils. Your goal is to make a proof that is accurate, easy to follow, and ready to reuse on your menu prototype board for the cafeteria staff member. As you work, explain your thinking to your teammates, label your visuals, and revise your proof after feedback.

Success criteria

You are done when your team has completed an annotated proof frame that includes: 1) a correct comparison of a snack portion using a visual model connected to 1/2, 2) a correct tenths-to-hundredths equivalent fraction shown on a grid, 3) a correct multiplication or multi-digit computation with matching visual model and equation, 4) labels or sentence-frame explanations that tell how you know the answer is correct, and 5) at least one revision based on partner feedback. You can also explain which strategy your team chose and why it fits the problem. In your reflection, you can name one math strategy you used and one way you helped your team work respectfully.

Facilitator notes

Keep the pace brisk so the activity stays a mini-lesson and not a full independent work block. Since the class has been building multiplication strategies across earlier sessions, explicitly connect the area model and partial products to the standard algorithm so students see the algorithm as another representation, not a separate trick. For students with varying reading levels, read the menu card aloud, chunk the proof frame into one section at a time, and offer icons or highlighted prompts for compare, rename, solve, and explain. Encourage students to choose the tool that best fits the problem rather than requiring every tool in every proof, but ensure the final frame includes fraction reasoning and multiplication or multi-digit computation. Watch for common pitfalls: students shading the wrong number of hundredths, comparing fractions without referring to the same whole, misaligning digits in the algorithm, or writing an equation that does not match the visual model. If teams finish early, ask them to improve audience clarity by circling the claim, underlining evidence, and adding one sentence that a cafeteria staff member would understand quickly. Use the critique round to normalize revision and build confidence before students move into sketching multiple menu options in the next activity.

Resources

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