Decimal Diner Teacher Guide
Decimal Diner
Grade 3 • Mathematics: Whole Numbers & Decimals
Duration
45 Minutes
Learning Objective
Students will differentiate between whole numbers and decimals by identifying and representing mixed numbers (e.g., 1.5, 2.5) using visual models, fractions, and money.
Materials List
- Decimal Diner Slides
- "Mixed Number Match-Up" Cards
- "Cookie Reflection" Journal Page
- Classroom Discussion Cards
- Video: Decimals for Kids | Homeschool Pop
Key Vocabulary
- Decimal Point: The dot between parts and wholes
- Whole Number: Complete units (1, 2, 3)
- Mixed Number: A whole and a decimal combined
Lesson Procedure
5 MIN
Warm-up: The Bouncy Ball Hook
Watch the 'Bouncy Ball' intro (0:00-1:00). Pause at 1:00 when the price $0.50 appears.
"Is $0.50 more or less than $1.00? How do we know?" (Look for students to identify the '0' in the dollars place).
10 MIN
Viewing: Donut & Apple Models
Watch segments 2:00-4:15. Focus on how the narrator writes '2.5'.
- 2:45: Pause on the donuts. "If we have one whole and another half, how many do we have?"
- 3:54: Note the visual of 2.5 apples. Highlight that ".5" means exactly half.
15 MIN
Mixed Number Match-Up
Hand out match-up cards (Visual, Fraction, Decimal). Students must 'mix and mingle' around the room to find the other two people whose cards match their own to form a "Trio."
10 MIN
Reflection & Journaling
Distribute the Reflection Journal page. Students respond to the cookie prompt using both writing and drawing to show their thinking.
Extension: Grocery Hunt
Provide grocery store flyers. Ask students to circle prices that include decimals (e.g., $1.99, $2.50). Can they find any prices that are "whole numbers" with no cents?
Decimal Diner Slides Deck
Grade 3 Math
Decimal Diner
Serving up wholes, parts, and everything in between!
Decimals
Real Food
Money
Bouncy Ball Intro
0:00 - 1:25
Embedded media
The Big Question:
Is $0.50 more or less than $1.00?
"Decimals show us numbers that aren't whole numbers."
The Decimal Point
Whole Part
2
Whole Apples
Decimal Part
.5
Half of an Apple
Total: 2.5
Donuts & Apples
2:00 - 4:15
Embedded media
Did You See?
- 1.5 = One and a half
- 0.5 = Exactly half
- 2.5 = Two and a half
Mixed Number Match-Up
Find your Match Trio! Look for the people holding:
The Visual
2.5
The Decimal
2 1/2
The Fraction
Reflection Time
"If I have 3.5 cookies, do I have enough to give 4 friends one whole cookie each?"
Why or why not?
Cookie Reflection Journal Prompt
Cookie Reflection
The Decimal Diner Journal
Name:
Date:
The Cookie Dilemma
If I have 3.5 cookies, do I have enough to give 4 friends one whole cookie each?
Show your work with a drawing
Explain your answer (Use the word "decimal")
I used a drawing
I explained my why
I used the word "decimal"
Mixed Number Matchup Key
Match-Up Answer Key
Decimal Diner • Activity Teacher Reference
| Set | Visual Description | Decimal | Fraction |
|---|
| A | 1 Whole Pizza + 1/2 Pizza | 1.5 | 1 1/2 |
| B | 2 Whole Apples + 1/2 Apple | 2.5 | 2 1/2 |
| C | 1/2 Circle (No wholes) | 0.5 | 1/2 |
| D | 1 Whole Donut + 1/4 Donut | 1.25 | 1 1/4 |
| E | 2 Whole Pizzas + 1/4 Pizza | 2.25 | 2 1/4 |
| F | 3/4 Circle (No wholes) | 0.75 | 3/4 |
Teaching Tip:
Students may confuse 1.5 with 1.25 because they see the "5" as "half". Remind them that 0.5 is like 50 cents (half a dollar) and 0.25 is like a quarter (one fourth). Use the pizza and apple models to reinforce the physical size of the parts.
