Mission 1: Place Value Models

Overview

Students begin Unit 1, “Navigating Number Adventures,” by building and interpreting numbers using base ten blocks and visual models. They practice representing the same number in standard form, expanded form, and word form, and explain how their model matches the number.

Learning intentions

• Students will be able to model a given number using base ten blocks (ones, tens, hundreds).
• Students will be able to represent numbers in standard form, expanded form, and word form.
• Students will be able to explain the place value relationships shown in their model.
• Students will be able to connect a visual model to the value of each digit.

Success criteria

• I can build the correct base ten representation for a number (using blocks accurately).
• I can write the number in standard form, expanded form, and word form correctly.
• I can explain how many ones, tens, and hundreds are in my model using place value language.
• I can check whether my representation makes sense using my model.

Curriculum links

• Understand and use place value to represent whole numbers through 1,000.
• Compare and reason about whole numbers using place value and expanded form ideas.
• Use models (like base ten blocks) to represent numbers and connect representations.
• Write number names and expanded expressions from a given numeric representation.

Lesson structure (30 minutes)

1. 0–3 — Warm-up: “Number of the Day” quick build Teacher displays a digit card (e.g., 342). Students quickly show it with small group base ten blocks at their table. Teacher asks, “What does the 3 mean? What does the 4 mean?” Students respond with place value terms (hundreds, tens, ones).

2. 3–10 — Mini-lesson: Standard, expanded, word forms Teacher models 342 using blocks: 3 hundreds flats, 4 tens rods, 2 ones cubes. On the board, teacher writes:

• Standard form: 342
• Expanded form: 300 + 40 + 2
• Word form: three hundred forty-two Teacher emphasizes that each digit’s value depends on its place.

3. 10–18 — Guided practice: “Build it, Write it, Explain it” stations Students (15 total) work with the teacher at one station while others use independent Montessori-style materials. Each student receives one number between 100 and 999.

• Build it with base ten blocks
• Record standard form, expanded form, and word form
• Write or say one sentence explaining their model (example: “My 5 is in the tens place, so it represents 50.”)

4. 18–25 — Whole-class share: Explain reasoning with a class model Teacher selects 3–4 student examples (or uses anonymous work). For each, teacher prompts:

• “What does each part of the model represent?”
• “Which form shows the same value the clearest?” Students justify by pointing to blocks and matching them to the written expressions and word names.

5. 25–30 — Exit ticket: model-match check Teacher reads one number aloud (e.g., 507). Students show the model with blocks for 20 seconds, then answer on a recording sheet:

• Standard form: ____
• Expanded form: ____ + ____ + ____
• Word form: ____ Students also add a short explanation: “The ____ digit is worth ____ because ____.”

Resources

• Base ten blocks set per student or per table (hundreds flats, tens rods, ones cubes)
• Number cards (100–999) and digit-place cards (hundreds/tens/ones)
• Recording sheet template with three boxes: standard, expanded, word
• Whiteboard/markers or document camera to model the example
• Visual place value mats (hundreds/tens/ones columns)
• Small sentence frames for explanations (for example: “The ____ is worth ____ because it is in the ____ place.”)
• Optional: word-form number cards for quick checks

Assessment

• Formative observation during guided practice: accuracy of block models and correct recording of forms.
• Quality of explanation: students can link digits to their place value using their model.
• Exit ticket results: identify common errors (like writing 342 as 300 + 4 + 2 or misnaming word form).

Differentiation

• Support for struggling learners
• Provide a place value mat with labeled columns and color-coded sectioning (hundreds/tens/ones).
• Use smaller starting numbers (e.g., 101–399) for the first practice while still meeting the same learning goals.
• Offer sentence frames and allow verbal responses before writing.
• Support for students needing additional practice
• Permit “check-and-fix” time: students compare their written expanded form to the blocks they built.
• Extension for advanced learners
• Give a number with missing form: “Build 6 hundreds, 2 tens, and 7 ones—write the standard and word form.” (Students generate multiple representations from the model.)
• Ask students to create a “spot-the-error” explanation: provide a wrong expanded form and have them prove what is incorrect by pointing to blocks.
• EAL/SEN strategies
• Pre-teach key language through visuals: hundreds, tens, ones; expanded form; word form.
• Keep work time structured: Build → Write → Explain using consistent steps and modeling.
• Reduce writing load if needed (student can dictate word form while teacher or peer transcribes).

Extension (optional)

• Students create a large classroom poster: “Numbers in Three Ways.”
• Each student (or pair) contributes one number and displays it in standard form, expanded form, and word form, with a small sketch of their base ten model (hundreds/tens/ones).
• Advanced learners can add a brief “How I know” line explaining one place value relationship from their model.