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Picture This: Math Within 20

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Jennifer Dorman

Tier 1
For Schools

Lesson Plan

Picture This Lesson Plan

Students will use visual models—number lines, ten-frames, and part–part–whole diagrams—to confidently add and subtract within 20, building strong number sense.

Visual strategies help first graders internalize number relationships, support diverse learners, and lay the groundwork for abstract arithmetic by making addition and subtraction concrete and engaging.

Audience

1st Grade

Time

30 minutes

Approach

Guided visual modeling with gradual release.

Materials

  • Number Line Visuals, - Ten-Frame Worksheets, - Part-Part-Whole Diagram Templates, - Independent Practice Problem Sheet, and - Exit Ticket Worksheet

Prep

Teacher Preparation

10 minutes

  • Print or prepare digital copies of Ten-Frame Worksheets and Part-Part-Whole Diagram Templates.
  • Project Number Line Visuals for whole-class display.
  • Make one Independent Practice Problem Sheet and one Exit Ticket Worksheet per student.
  • Review today's objectives and familiarize yourself with each visual tool.

Step 1

Warm-Up: Number Line Exploration

5 minutes

  • Gather students on the carpet and project the Number Line Visuals.
  • Point to various numbers; have students count aloud forward and backward.
  • Ask: “If we start at 6 and move 4 jumps, where do we land?”
  • Invite volunteers to demonstrate jumps on the projected line.

Step 2

Main Activity 1: Adding on a Number Line

7 minutes

  • Distribute individual number line copies (or use whiteboards).
  • Model solving 8 + 5 by marking 8 and making 5 jumps.
  • Students work with a partner on two problems, drawing jumps and stating their thinking.
  • Circulate, prompt use of correct spacing and counting.

Step 3

Main Activity 2: Ten-Frame Strategies

7 minutes

  • Introduce Ten-Frame Worksheets.
  • Demonstrate 7 + 6 by filling one ten-frame and moving into the next.
  • Have students complete two problems, counting “how many more to ten?” and “how many left after ten?”
  • Encourage partners to explain their strategy aloud.

Step 4

Main Activity 3: Part–Part–Whole Diagrams

5 minutes

  • Show Part-Part-Whole Diagram Templates.
  • Solve 12 – 5: place 12 in the whole, draw one part of 5, and find the other part.
  • Students complete one diagram for an addition problem and one for subtraction.
  • Discuss how breaking numbers into parts helps calculation.

Step 5

Independent Practice

4 minutes

  • Hand out the Independent Practice Problem Sheet.
  • Students independently solve a mix of addition and subtraction within 20 using any preferred visual.
  • Encourage them to choose the strategy that feels easiest.

Step 6

Cool-Down & Exit Ticket

2 minutes

  • Distribute the Exit Ticket Worksheet.
  • Students complete one quick problem of their choice using one visual model.
  • Collect tickets to gauge individual understanding and plan next steps.
lenny

Slide Deck

Picture This: Math Within 20

Using pictures to add and subtract within 20.
First Grade | 30 minutes

Welcome everyone! Today we’re learning how to add and subtract within 20 using pictures and visual tools. Introduce yourself and get students excited about exploring number lines, ten-frames, and part–part–whole diagrams.

Lesson Objectives

• Use a number line to add within 20.
• Use ten-frames to add within 20.
• Use part–part–whole diagrams to add and subtract within 20.

Read the objectives aloud. Explain that students will practice three different visual methods and then choose their favorite for independent work.

Warm-Up: Number Line Exploration

  1. Project Number Line Visuals.
  2. Count aloud forward and backward.
  3. Ask: “Start at 6. Move 4 jumps. Where do you land?”
  4. Invite volunteers to show their jumps.

Project the number line and gather students on the carpet. Ask volunteers to jump forward and backward. Prompt them to think aloud as they count.

Main Activity 1: Adding on a Number Line

• Model: 8 + 5 → start at 8, make 5 jumps.
• Students work in pairs on two problems.
• Draw jumps, label each move, and say their thinking.

Demonstrate one example (8 + 5). Show how each jump adds one. Then pair students to solve two practice problems on mini number lines.

Main Activity 2: Ten-Frame Strategies

• Introduce Ten-Frame Worksheets.
• Example: 7 + 6 → fill 3 to make 10, 3 + 4 left.
• Students complete two problems, counting “to ten” and “past ten.”

Show how filling one ten-frame to ten then moving to the next helps keep track. Ask partners to explain how many more to ten and how many past ten.

Main Activity 3: Part–Part–Whole Diagrams

• Show Part-Part-Whole Diagram Templates.
• Example: 12 – 5 → whole = 12, one part = 5, find the other.
• Students solve one addition and one subtraction.

Explain the whole, part, and part circles. Model subtraction (12 – 5) then have students complete one addition and one subtraction diagram.

Independent Practice

• Hand out Independent Practice Problem Sheet.
• Mix of addition and subtraction within 20.
• Students choose number line, ten-frame, or diagram.

Distribute the practice sheet. Encourage students to pick their favorite visual strategy. Circulate and support as needed.

Cool-Down & Exit Ticket

• Give each student an Exit Ticket Worksheet.
• Complete one chosen problem with a visual.
• Collect for assessment.

Pass out exit tickets. Ask each student to complete one problem using their preferred visual. Collect to check understanding and plan next steps.

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Worksheet

Ten-Frame Worksheets

Blank Ten-Frame Template

Use these two ten-frames to help you with today’s problems. Draw counters in the boxes below.

Problems

  1. 7 + 6 = ______

Draw counters to show 7, then add 6 more. Count all to find the answer.




  1. 4 + 9 = ______

Draw counters to show 4, then add 9 more. Count all to find the answer.




Need more space? Use extra ten-frames on the back of your paper!

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lenny

Worksheet

Part–Part–Whole Diagrams

Use the template below to break numbers into two parts. Write the total (whole) in the top circle and the two parts in the bottom circles.

   (       )
  /         \
(   )     (   )

Problems

  1. 8 + 7 = ___

Use the diagram to show how 8 and 7 come together. Label each part and the whole.

   (       )
  /         \
(   )     (   )







  1. 12 – 5 = ___

Place 12 in the whole. One part is 5. Find and write the missing part.

   (       )
  /         \
(   )     (   )







  1. 14 = __ + __

Break 14 into any two parts you choose. Fill in the diagram.

   (       )
  /         \
(   )     (   )











  1. __ + 6 = 14

One part is 6, and the whole is 14. Find the missing part and complete the diagram.

   (       )
  /         \
(   )     (   )







Challenge: Create your own part–part–whole problem and solve it using this template.

Need more practice? Draw extra diagrams on the back of your paper!

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lenny

Worksheet

Independent Practice Problem Sheet

Instructions: Use any visual model you like—Number Line Visuals, Ten-Frame Worksheets, or Part-Part-Whole Diagram Templates—to solve each problem. Draw your model and write your answer in the space provided.

  1. 9 + 8 = ______







  1. 15 – 7 = ______







  1. 11 + 5 = ______







  1. 14 – 9 = ______







  1. 6 + 13 = ______







  1. 18 – 6 = ______







Challenge: Create your own addition or subtraction problem within 20. Use a visual model to solve it and share with a partner!

Great work! Be ready to share which visual strategy helped you most and why.

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lenny

Worksheet

Exit Ticket Worksheet

Choose one problem to solve. Use any visual model (Number Line Visuals, Ten-Frame Worksheets, or Part-Part-Whole Diagram Templates).

Problems (circle one):

( ) 13 + 4 = ______

( ) 16 – 7 = ______

Draw your model below:










Write your answer: ______

Which visual did you use? ______



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