Bar Builders Teacher Guide
Bar Builders
Teacher Facilitation Guide
Objective
Students will represent addition word problems using physical manipulatives (concrete) before drawing them (abstract).
Materials
- Linking Cubes (Unifix)
- Bar Builder Worksheet
- Crayons/Pencils
- Bar Builders Slides
Misconceptions
Students may struggle with "what do I do with these numbers?" The bar model addresses this by organizing data visually before choosing an operation.
Key Vocab
Bar Model
A visual way to show a number using a rectangle.
Total / In All
Keywords that signal addition.
1
Number Bond Lightning Round (5 min)
Call out a whole number (e.g., 5, 8, or 10).
Students quickly hold up fingers to show a pair of "parts" that make that "whole" (e.g., if you say "5", they might hold up 2 fingers on one hand and 3 on the other).
Tip: Do this rapidly to build fluency and reinforce the part-part-whole concept.
2
Video & Guided Discussion (5 min)
Watch the first segment (0:00-1:06) of the video.
Pause at 0:22
"What are the two important numbers? How might we draw this?"
Pause at 0:24
"Why is the blue bar longer than the yellow bar?" (Discuss scale).
3
Main Activity: Build the Bar (20 min)
Problem 1: Re-watch the books segment. Students build a blue train of 12 and a yellow train of 6. Snap them together to find the total (18).
Problem 2: Watch the apple segment. Students build a green train of 8 and a red train of 9. Snap them together to find the total (17).
Challenge: "Before counting, will this total be more or less than 20? How do you know?"
4
Reflection & Extension (10 min)
Students use the Bar Builder Worksheet to draw their models from the activity.
Extension: On the back (or final section), students pick two numbers of their own, build them with cubes, then draw and label them.
Bar Builders Slides
Bar Builders
Adding with Models
Warm Up
Lightning Round
When I say a number,
show me two parts on your fingers!
🖐️
Part
✌️
Part
Problem 1: Ethan's Books
Watch & Pause
Embedded media
Pause at 0:24
Why is the blue bar longer than the yellow bar?
Let's Build It!
1
Build a Blue Bar
12 Cubes
2
Build a Yellow Bar
6 Cubes
Snap them together! What is the Total?
Problem 2: Apple Sales
Predict & Build
Embedded media
Predict at 1:39
Will the total be more or less than 20?
Build the Apples!
1
Green Apples
8 Cubes
2
Red Apples
9 Cubes
Combine them! How many In All?
Bar Builder Goal
A Bar Model helps us see the Parts and the Total of a story problem.
Build
Draw
Solve
Bar Builder Worksheet
Bar Builders!
Name
Date
1
Ethan's Library Books
Draw the bar model you built with cubes.
Monday (12)
Tuesday (6)
Total (? In All)
12
6
=
Sum
2
The Apple Shop
Draw your green and red bar model here.
Label your parts and the total!
=
Part
Part
Sum
?
Extension: My Own Story
Pick two numbers. Build it with cubes, then draw it below!
Part 1 Number
Part 2 Number
Draw and label your own parts and total above!
Bar Builder Answer Key
Answer Key
Bar Builders Key
Addition to 20 with Bar Models
1
Ethan's Library Books
12
6
18
12 + 6 = 18
2
The Apple Shop
8
9
17
8 + 9 = 17
Grading Checklist
Scale: Are the bars drawn with roughly correct lengths? (e.g., 12 is longer than 6).
Labels: Are both parts labeled with the correct numbers?
Total: Is the whole bar labeled with the sum?
Equation: Does the number sentence match the model?
