Decimal Dash Slides Guide Decimal Dash Slides
Visual Presentation Guide
Slide 1
The Problem
0.4 into 1.2
"We can't divide by a decimal... it's too messy!"
Slide 2
The Secret Rule
The Outside Number (Divisor)
MUST BE A WHOLE NUMBER!
0.4
4
Slide 3
Step 1: The Dash!
Move the decimal to the RIGHT until the number is whole.
0 . 4
0.4 4
Slide 4
Step 2: The Copycat
Whatever the Outside does,
Outside
0.4 4
1 Jump Right
Inside
1.2 12
1 Jump Right
Slide 5: The Final View
Teacher Talk: "The New Problem"
1.2 ÷ 0.4
12 ÷ 4
Why do we do this?
It's like zooming in! The answer stays exactly the same, but the numbers are easier to work with.
The Result
3
1.2 ÷ 0.4 is the same as 12 ÷ 4!
Decimal Shift Map Reference Decimal Dash Map
The "Shift & Slide" Cheat Sheet
NAME:
DATE:
STEP 1
Fix the OUTSIDE
Move the decimal to the RIGHT until the divisor is a Whole Number.
0.2 → 2
STEP 2
Copy on the INSIDE
Move the decimal inside the SAME number of spaces.
0.8 → 8
STEP 3
Shoot it UP
Move the decimal straight UP into your answer area.
↑ . ↑
Practice Blueprint
Outside
0.5
MATCH MOVES
Inside
2.5
New Problem
25 ÷ 5
Try the "Shift" yourself:
0.3
into
0.9
?
WHOLE NUMBERS
REMEMBER: If the outside moves 1 time, the inside MUST move 1 time. If the outside moves 2 times, the inside moves 2 times. They are best friends!
Pizza Party Practice Worksheet Pizza Party Practice
Slice and Divide Decimal Challenge
Chef Name:
Table No:
The Pizza Problem
You are hosting a pizza party! You have $2.40 to spend on mini pizzas. Each mini pizza costs $0.60.
Equation
$2.40 ÷ $0.60
CHALLENGE #1
Do the "Decimal Shift" to make whole numbers:
The Cost (Outside)
0.60
The Money (Inside)
2.40
CHALLENGE #2
Solve your new "Whole Number" problem:
÷
=
How many mini pizzas can you buy?
Check your work:
Does moving the decimal change the answer? YES / NO
Decimal Dash Teacher Guide Teacher Instruction Guide
Lesson: Decimal Dash Division (SPED Intro)
30 Minutes
Learning Goals
Students will understand that the divisor must be a whole number before dividing.
Students will practice "shifting" the decimal in both the divisor and dividend simultaneously.
Students will connect decimal movement to the concept of "zooming in" (Power of 10).
Lesson Flow (30 Mins)
00-05
The "Messy" Hook
Show Slide 1. Ask: "Would you rather divide $1.20 by 4 pennies, or 120 by 4?" Emphasize that decimals make the divisor "messy" and hard to read.
05-15
Visual Modeling
Use the Decimal Dash Slides . Introduce the "Secret Rule." Physically model the "jump" on the whiteboard with a bright marker. Hand out the Decimal Shift Map for students to follow along.
15-25
Pizza Practice
Guide students through the Pizza Party Practice worksheet. Do Challenge #1 together, then let them attempt Challenge #2 independently or with a partner.
25-30
Check for Success
Exit Question: "If I move the decimal 2 times on the outside, how many times do I move it on the inside?"
SPED Strategies
Visual & Sensory
Use Highlighters : One color for divisor shifts, another for dividend shifts.
Physical Jumps : Have students use their fingers or a "decimal marker" to physically slide along the page.
Cognitive Load
Limit the numbers. Focus only on shifting today, not the actual long division algorithm if students aren't ready.
Use 1:1 correspondence with the pizza icons.
Common Misconceptions
"Students often only shift the divisor and forget to shift the dividend."
Fix: Use the "Best Friends" metaphor. They do everything together! If one jumps, the other jumps.
Decimal Dash Answer Key Answer Key
Pizza Party Practice & Shift Map
Shift Map Results
Practice Problem 1 (Guided)
0.5 5
2.5 25
New Problem: 25 ÷ 5 = 5
Practice Problem 2 (Independent)
0.3 3
0.9 9
New Problem: 9 ÷ 3 = 3
Pizza Party Results
Challenge #1: The Shift
Outside (0.60)
6
Inside (2.40)
24
*Note: Moving 1 time to get 6 and 24 is correct. Moving 2 times to get 60 and 240 is also correct and yields the same answer.
Challenge #2: The Solution
24 ÷ 6 =
4
You can buy 4 mini pizzas.
Quick Check:
Does moving the decimal change the answer? NO
Teacher Reminder: Success in this lesson is defined by the student correctly moving the decimal points in tandem. If they struggle with the division facts (24÷6), allow the use of a calculator or multiplication chart to keep the focus on the "Shift" strategy.
