Smart Shopping Spree!: Decimals to the Hundredths

Introduction (5 minutes):

Start by reviewing the concept of decimals.

What are decimals? Decimals are a way to represent parts of a whole. We use them to show amounts that are less than one whole number.
Place Value Review: Remind students of the place values to the right of the decimal point (tenths, hundredths). You can draw a place value chart on the board.
Money Talk: Connect decimals to money. Explain that the cents part of a price is like the hundredths place in a decimal (e.g., $1.25 is one whole dollar and 25 hundredths of a dollar).
 

Activity 1: Adding Decimals (15 minutes)

Shopping Scenario: Present a scenario where students are buying items at a store. Use real-world examples like:
"You want to buy a notebook for $2.75 and a pen for $1.50. How much will you spend in total?"
Model the Solution:
Write the prices vertically, aligning the decimal points.
Add each place value column, starting from the right (hundredths, then tenths, then ones).
Show how to carry over if necessary.
Emphasize the importance of keeping the decimal point in the answer.
Guided Practice: Work through a few more examples together, gradually increasing the difficulty.
"You buy a book for $7.99 and a bookmark for $0.45."
"You buy a toy car for $3.25, a pack of stickers for $1.99, and a candy bar for $0.89."
 

Activity 2: Subtracting Decimals (15 minutes)

New Scenario: Introduce a scenario involving discounts or calculating change.
"You have $10.00. You buy a game for $8.50. How much change will you get back?"
Model the Solution:
Write the amounts vertically, aligning the decimal points.
Subtract each place value column, starting from the right.
Show how to borrow if necessary.
Again, emphasize the importance of the decimal point.
Guided Practice: Provide more examples for students to practice:
"A shirt originally costs $12.95, but it's on sale for $9.99. How much do you save?"
"You have $5.50. You buy a snack for $2.75. How much money do you have left?"
 

Wrap-up (5 minutes)

Review the steps for adding and subtracting decimals.
Discuss real-life situations where these skills are useful (e.g., budgeting, comparing prices, calculating discounts).
 

Assessment:

Provide students with printed copies of the performance task linked in the resources tab. Observe student participation and provide feedback during the activities.
Collect student work and assess their understanding of adding and subtracting decimals.
Assign word problems involving shopping scenarios for homework.

differentiation: Use manipulatives like base-ten blocks to represent decimals.

extension: Have students create their own shopping lists and calculate the total cost. Use store flyers to create real-world shopping problems for the class to solve.

Use the performance task linked in the resources tab to assess student learning outcomes.