This cash flow classroom activity gives introductory business and accounting students 45 minutes to explain why a profitable company can struggle to pay its bills. Students calculate profit, track cash, and decide whether a small business can afford a growth order. The lesson runs on paper with a calculator.
Download the free cash flow vs profit worksheet (PDF) and the separate instructor answer key (PDF). Both use a fictional example in US dollars. No ClassTycoon account is needed.
Spend the first five minutes asking students what profit tells an owner and what a bank balance tells them. Profit measures revenue earned minus expenses incurred over a period. Cash flow measures money received and paid during that period. A cash balance is the amount available at a particular time. These figures answer different questions.
Introduce a campus notebook business with $800 in opening cash. During September, it delivers 300 notebooks at $12 each. The notebooks cost $4 each, and September operating expenses are $1,200. All notebooks are sold and delivered during September. There is no opening or closing inventory in the base case.
Customers pay $1,800 during September and owe the remaining $1,800, which they are expected to pay in October. The business pays the full $1,200 notebook cost and all $1,200 of operating expenses during September. Assume September customer receipts arrive before those payments. Exclude tax, interest, equipment purchases, depreciation, borrowing, and owner withdrawals.
Give pairs ten minutes to calculate September revenue and profit. Revenue is 300 multiplied by $12, or $3,600. The cost of the notebooks sold is 300 multiplied by $4, or $1,200. Subtract that cost and $1,200 of operating expenses to obtain $1,200 in profit.
The unpaid $1,800 still forms part of September revenue because the business has delivered the notebooks and earned the sale. The amount customers owe is called accounts receivable. This exercise uses accrual accounting, which records revenue when earned and expenses when incurred rather than waiting for the related cash payment.
Use the next ten minutes to build a separate cash calculation. September cash receipts are $1,800, and cash payments total $2,400. Net cash flow is therefore negative $600. Add that change to the $800 opening balance to obtain $200 in closing cash.
Follow the cash balance through September in the order assumed here. The customer receipts arrive first. The business can pay both September bills, but only $200 remains. Each bar shows cash available after that step, rather than the size of the payment.
See the cash balance animation
| Step | Cash movement | Cash balance |
|---|---|---|
| Opening cash | No movement | $800 |
| Customer receipts | +$1,800 | $2,600 |
| Pay for notebooks | -$1,200 | $1,400 |
| Pay operating expenses | -$1,200 | $200 |
| Item | Profit calculation | Cash flow calculation |
|---|---|---|
| Sales earned / cash received | $3,600 | $1,800 |
| Notebook cost / payment | -$1,200 | -$1,200 |
| Operating expense / payment | -$1,200 | -$1,200 |
| Result | $1,200 profit | -$600 net cash flow |
Customers still owe $1,800. Opening cash is a balance, so it is excluded from both result columns. Add the negative $600 net cash flow to $800 opening cash to get $200 closing cash.
Ask students to explain the gap without changing either answer. The business made $1,200 in profit while its cash fell by $600. The $1,800 difference is the increase in money owed by customers. Under these assumptions, subtracting that increase from profit gives net cash flow. Other businesses may also have inventory, unpaid supplier bills, or noncash expenses that affect the comparison.
Spend ten minutes on a growth decision. Immediately after the September payments, a supplier offers an additional batch of notebooks for $900, payable in full before delivery. The next customer payment will arrive later. Can the business accept the order using its current cash?
Its $200 balance leaves a $700 funding gap. Forecasting more profit does not fill that gap before payment is due. A calculated balance of negative $700 represents missing funding, not permission to overdraw the bank account.
Ask pairs to compare waiting with collecting an existing customer payment early. If the full $1,800 arrives before the supplier payment, cash rises to $2,000 and falls to $1,100 after paying $900. If only $900 arrives early, cash rises to $1,100 and falls to $200 after payment. These are separate alternatives, with no other intervening transactions. Early collection requires customer agreement.
| Early collection | Cash before $900 order | Cash after payment |
|---|---|---|
| $0 | $200 | Cannot pay, $700 short |
| $900 | $1,100 | $200 |
| $1,800 | $2,000 | $1,100 |
Each option starts with the same $200 September closing balance. Collecting an existing customer debt changes cash, but creates no new revenue or profit.
Collecting an existing receivable does not create another sale or another $1,800 of profit. The new supplier payment initially creates a prepayment, then inventory when the notebooks arrive. It becomes a cost of goods sold when those notebooks are sold. Keep this extension separate from the September base case.
Use the final ten minutes for an individual recommendation. Each student should state September profit, net cash flow, closing cash, and the funding gap. Then ask whether to wait, seek an earlier customer payment, or negotiate supplier terms. Require a payment timeline and one risk, such as a customer paying late. There is no single best option without knowing the terms and consequences.
During the debrief, check that students distinguish revenue from receipts and net cash flow from closing cash. Watch for counting the October collection as a second sale or treating the growth payment as an immediate expense. Assess the calculation and the reasoning behind the recommendation.
This is a short cash forecast exercise, not a complete statement of cash flows. For the accounting background, see OpenStax’s explanation of why cash flows can differ from profit.
Use the break-even analysis classroom activity first if students need practice separating revenue, costs, and profit. Continue with the capital budgeting lesson when they are ready to evaluate longer-term investment decisions.
For a later class, explore the ClassTycoon simulations and ask each Team Company to explain how its decisions affect profit and available cash. Use the chosen scenario’s actual reports and payment rules. The delayed customer payments in this paper exercise are teaching assumptions, not a claim about ClassTycoon’s simulation mechanics.
Print one worksheet per pair and keep the answer key for the debrief. Ask students to commit to a growth decision before showing the worked answers.