Math for Business Operations

Applied Accounting with Excel

UNIT07 - Lesson 2

Inventory Cost Flow Foundations

45 minutes
Lesson Overview

Lesson Focus

Inventory flow concepts, beginning inventory, purchases, and COGS

Key Unit Objectives

Enduring Understandings:

  • Inventory valuation methods directly impact reported profits, tax obligations, and business decision-making
  • FIFO, LIFO, Weighted Average, and Specific Identification produce different COGS and ending inventory values
  • Accurate inventory tracking is essential for business sustainability and investor confidence
  • The inventory equation (Beginning Inventory + Purchases − COGS = Ending Inventory) must always reconcile

Lesson Activities

Activity 1: Inventory Flow Concepts
15 minutes

Why businesses track inventory costs and the inventory equation

Details:

  • Connect to Sarah's case: How does inventory flow through a business?
  • Business rationale: matching principle and cost of goods sold recognition
  • The inventory equation: Beginning Inventory + Purchases − COGS = Ending Inventory
  • Introduction to the four inventory valuation methods
The Inventory Equation

Beginning Inventory + Purchases − COGS = Ending Inventory

  • Beginning Inventory: Value of inventory at start of period
  • Purchases: Additional inventory acquired during period
  • COGS: Cost of inventory items sold during period
  • Ending Inventory: Value of inventory remaining at period end
Activity 2: Inventory Schedule Setup Demo
15 minutes

Demonstrate inventory schedule setup in Excel

Details:

  • Build a basic inventory schedule with date, quantity, unit cost, and total cost columns
  • Enter beginning inventory and purchase transactions
  • Calculate goods available for sale
  • Guided practice with sample inventory data
Activity 3: Guided Practice
10 minutes

Students practice building inventory schedules

Details:

  • Students create their own inventory schedule from provided data
  • Verify goods available for sale calculations
  • Peer review for accuracy
  • Preview Day 3: FIFO vs. LIFO logic
Activity 4: Checkpoint & Preview
5 minutes

Check understanding and preview next lesson

Details:

  • Quick check: Can students calculate goods available for sale?
  • Preview: How do we decide which costs go to COGS vs. ending inventory?
  • Preview Day 3: FIFO vs. LIFO — two ways to value the same inventory
Required Materials
  • Inventory flow guide
  • Sample workbook template
  • Practice inventory dataset
  • Inventory schedule template
Differentiation Strategies

For Struggling Students

  • • Formula templates: Pre-built Excel structures with guided parameter entry
  • • Step-by-step calculation guides: Visual walkthroughs for all four inventory methods
  • • Simplified datasets: Reduced complexity while maintaining authentic business context
  • • Peer tutoring: Pairing with students strong in Excel or business concepts
  • • Alternative assessment: Oral presentation option with reduced Excel complexity requirements

For Advanced Students

  • • Advanced Excel features: Explore LIFO reserve and tax implications as extension activity
  • • Complex scenarios: Multiple inventory categories and sensitivity analysis on purchase timing
  • • Leadership roles: Facilitate team strategic discussions and mentor struggling peers
  • • Extension analysis: Research industry-specific inventory practices and regulatory requirements
  • • Presentation enhancement: Develop sophisticated visual aids and executive summary documents

For English Language Learners

  • • Business vocabulary support: Glossary of inventory terms with visual aids and translations
  • • Calculation emphasis: Focus on quantitative skills while building language gradually
  • • Collaborative support: Mixed-language team structures with peer translation assistance
  • • Visual learning aids: Charts, diagrams, and flowcharts to support conceptual understanding
  • • Presentation alternatives: Option to focus on Excel demonstration with reduced verbal component