# Decimal Ops Project: Ordering From a Catalog

Students select items from a catalog and fill out an order form, calculating shipping, tax, and discounts.

## Materials Needed

- Labsheets (option)
- Access to online stores to find "items to purchase"

## Adaptations and notes

- Parents and students will need to understand that this is a fake buying activity
- The project was designed to do in the classroom with physical or online resources to find “items to buy”. You will have to adapt this to finding items that students would like to by on specific websites.
- You might decide to have students make-up items and approximate prices rather than look online. For example, a student might decide on a Xbox game system for $299.99. They can draw a picture of one and describe it. This will reduce online activity and searching.
- More questions can be asked about percents, ratios, and strategies involving them.

## Possible CCSS

### Grade 6

#### Ratios and Proportional relationships 6.rp

**Understanding ratio concepts and use radio reasoning to solve problems.**

3. Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.

c. Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent.

### Grade 7

#### Ratios and Proportional relationships 7.RP

**Analyze proportional relationships and use them to solve real-world and mathematical
problems**

3. Use proportional relationships to solve multistep ratio and percent problems. *Examples: simple interest, tax, markups and markdowns, gratuities and commissions,
fees, percent increase and decrease, percent error.*