Each one of the lessons in the GEDDES Lesson Plan Library brings up math words and math terms that students might not have heard before. Here is a list of all of the terms in each lesson that might be unfamiliar to students. Reviewing these terms can help expand vocabulary by introducing new words and connecting meaning to their application within each lesson.

### Lesson Plan 1: What’s on Sale at the School Store?

• Cost – The amount a store pays to purchase an item for inventory.
• Customer – Someone who pays for goods and/or services.
• Discount – The amount the retail price or selling price is reduced.
• Merchandise – Items offered for sale in a store.
• Retail Price – The price an item is sold for in a store (same as selling price).
• Selling Price – The price an item is sold for in a store (same as retail price).

### Lesson Plan 2: Charting and Graphing Sales

• Bar Graph - A chart that visually presents data as categories that vary in height.
• Pie Chart - A graph that displays data in a circular format. Each section of the pie chart represents a portion or percentage of the total.
• Table - Data that is displayed in a format using labeled columns and rows.

### Lesson Plan 3: Measuring Angles

• Acute Angle - Has a measurement between 0 and 90 degrees.
• Obtuse Angle - Has a measurement between 90 and 180 degrees.
• Protractor - A tool used to measure angles.
• Right Angle - Has an exact measurement of 90 degrees.
• Vertex - The meeting point of two lines or rays.

### Lesson Plan 4: Estimating School Store Purchases

• Estimate - To give an approximate calculation.
• Round - To give a close approximation of a number, a form of estimating.

### Lesson Plan 5: Paying with Coins

• Budget - A plan for saving or spending money.
• Coins - Form of money usually made of metal and in a flat, rounded shape.
• Currency - Coins, paper money, or anything used as a medium of exchange.
• Denomination - The face value of money.

### Lesson Plan 6: Analyzing Product Price and Sales Data

• Mean - The average, calculated by adding values (data) and dividing by the number of values (sample).
• Median - The middle value in a series of values placed in numerical order.
• Mode - The most common value in a series of values.
• Range - Difference between the largest and smallest numbers in a sample.
• Sample - A group of numbers.

### Lesson Plan 7: Calculating Sales Tax

• Revenue – Income; income collected by the government through taxes.
• Sales Tax - A state government tax charged for certain goods and services.
• Tax – A required fee paid to the government to support the government.

### Lesson Plan 8: Learning About Making Change

• Customer – Someone who pays for goods and/or services.
• Denomination – The face value of money.

### Lesson Plan 9: Tracking School Store Inventory

• Customer – Someone who pays for goods and/or services.
• Inventory – A list of goods or materials in stock and available to be sold.

### Lesson Plan 10: Determining Profit and Loss

• Cost of Goods Sold: The cost of selling goods or items; calculated as the opening merchandise inventory plus purchases minus closing merchandise inventory