Decimal Bootcamp Slides Decimal Bootcamp
Money Edition
Mastering Sales Tax & Decimal Fluency
Mission Objectives
01
Fluently multiply multi-digit decimals to calculate sales tax.
02
Fluently add multi-digit decimals to find the total cost of items.
03
Convert percentages to decimals by dividing by 100.
Warm-Up Drill
5:00
Addition Rule
12.45 + 3.8 = ?
Key: Line up the decimals!
Multiplication Rule
4.5 × 0.02 = ?
Key: Count the decimal places!
Quick Discussion: Why are the rules different?
The Cashier's Code
Step 1
Original Price × Tax Rate (as a decimal) = Sales Tax
Step 2
Original Price + Sales Tax = TOTAL COST
Expert Briefing: Setting the Problem
Watch until 2:00
Embedded media
PAUSE AT 0:45
How do you turn a percent into a decimal? Prediction check!
Expert Briefing: The Calculation
Watch until 5:36
Embedded media
PAUSE AT 2:00 & 5:36
Predict the setup! What is the #1 rule for the final addition?
The Golden Rounding Rule
"Whenever we are working with money, our final answer must go to the hundredths place (cents)."
Calculated Tax
4.46175
Final Rounded Tax
$4.46
Why does that '1' matter? Check the neighbor to the right!
Cashier vs. Calculator
The Cashier
Calculate tax by hand.
Round to the nearest cent.
Show all work on your sheet.
The Auditor
WAIT until work is done.
Check work with calculator.
Initial the worksheet if correct.
Switch Roles Every 3 Problems!
Decimal Bootcamp Worksheet Decimal Bootcamp: Money Edition
Topic: Multi-Digit Decimal Operations & Sales Tax
Name:
Date:
Step 1: Calculate Tax
Price × Tax Rate (Decimal) = Tax Amount
Step 2: Calculate Total
Price + Tax Amount = Total Cost
Rounding
Round to the nearest Hundredth (0.01)
Cashier vs. Auditor Activity
Cashier: Do work by hand | Auditor: Check with calculator after.
1
Item
Sneaker Drops
Price
$84.50
Tax Rate
6%
Auditor Check
Workspace: Calculate Tax Amount
Workspace: Calculate Total Cost
2
Item
Gamer Headset
Price
$120.99
Tax Rate
8.5%
Auditor Check
Workspace: Calculate Tax Amount
Workspace: Calculate Total Cost
3
Item
Skateboard Deck
Price
$55.00
Tax Rate
5.5%
Auditor Check
Workspace: Calculate Tax Amount
Workspace: Calculate Total Cost
Role Switch: Change Who Uses the Calculator!
4
Item
Graphic Novel Set
Price
$32.75
Tax Rate
4%
Auditor Check
Workspace: Calculate Tax Amount
Workspace: Calculate Total Cost
5
Item
Luxury Hoodie
Price
$64.20
Tax Rate
7.2%
Auditor Check
Workspace: Calculate Tax Amount
Workspace: Calculate Total Cost
6
Item
Collector Trading Cards
Price
$12.50
Tax Rate
9%
Auditor Check
Workspace: Calculate Tax Amount
Workspace: Calculate Total Cost
Decimal Bootcamp Exit Ticket Exit Ticket
Bootcamp Completion
Soldier Name:
The Final Purchase
You are purchasing a special edition backpack priced at $20.00. The sales tax rate in your city is 5%. Complete the two steps below to find your total cost.
1
Calculate the Sales Tax Amount
Show your multiplication work here:
Tax Amount:
$
2
Calculate the Final Total Cost
Show your addition work here:
Final Total:
$
Did you line up your decimals in step 2?
Bootcamp Graduate Status
Decimal Bootcamp Teacher Guide Instructor's Intel
Decimal Bootcamp: Money Edition
6th Grade Math
Mission Timeline
05 min
Warm-Up Drill
Quick drill on slide 3. Focus on the difference between addition (line up decimals) and multiplication (count places).
10 min
Expert Briefing (Video)
Watch the YouTube video. Use the pause points on slides 5 and 6 to engage students in predictive setup.
20 min
Cashier vs. Auditor Activity
Pair practice. One manual calculation (Cashier) and one verification check (Auditor). Switch roles every 3 problems.
10 min
Closure: Exit Ticket
Individual assessment. Students must calculate total cost of a $20 item with 5% tax.
Discussion Anchors
The "Why" of Dividing by 100: Ask students why dividing 7.5% by 100 moves the decimal left. Connect to place value (each jump is 1/10th the size).
The Multiplication Mystery: Why do we count decimal places instead of lining them up? Connect to fraction multiplication (e.g., tenths × hundredths = thousandths).
Real-World Rounding: What happens if we don't round? Can you pay $4.46175? Discuss the physical constraints of currency.
Worksheet Answer Key
#1: Tax: $5.07 | Total: $89.57
#2: Tax: $10.28 | Total: $131.27
#3: Tax: $3.03 | Total: $58.03
#4: Tax: $1.31 | Total: $34.06
#5: Tax: $4.62 | Total: $68.82
#6: Tax: $1.13 | Total: $13.63
Exit Ticket Key
Step 1: Tax
20.00 × 0.05 = $1.00
Step 2: Total
20.00 + 1.00 = $21.00
Teacher Tip:
Watch for students who forget to convert the tax rate to a decimal (e.g., multiplying by 6 instead of 0.06). This is the most common "Bootcamp Blunder"!
