Value added at a stage is its selling price minus the cost of what it bought in. Add up every stage and you get the final price.
This lesson is part of primary, secondary and tertiary activities. Sort each step by sector first, using classifying activities by what they do.
How do I calculate value added?
For each stage, subtract the price paid for inputs from the price the stage sells at. Do it in order, starting from the first stage.
Write the sum in full: selling price − input cost = value added. This avoids picking the wrong two numbers from the table.
Worked example: from cocoa to chocolate bar
This is an original chain with invented prices, per 100 bars’ worth of product.
| Stage | Sector | Sells at | Input cost | Value added |
|---|---|---|---|---|
| Farm grows cocoa beans | Primary | RM300 | RM0 | RM300 |
| Factory makes chocolate | Secondary | RM1 100 | RM300 | RM800 |
| Wholesaler distributes | Tertiary | RM1 300 | RM1 100 | RM200 |
| Shop sells bars | Tertiary | RM1 800 | RM1 300 | RM500 |
Check: 300 + 800 + 200 + 500 = RM1 800, which equals the final price. The chain adds up.
The largest value added is at the factory, RM800, which is 800 ÷ 1 800 = 44% of the final price. The smallest is the wholesaler, RM200.
A full statement: “The secondary stage adds the most value, RM800, because processing turns RM300 of beans into chocolate worth RM1 100.”
The mistake that loses marks
A common error is to read the selling price as the value added. A student writes “the shop adds RM1 800”.
| Item | Wrong | Right |
|---|---|---|
| Shop value added | RM1 800 | RM1 800 − RM1 300 = RM500 |
| Largest stage | Shop | Factory, RM800 |
The shop’s selling price includes everything done earlier, so using it gives the wrong winner. Subtract the inputs, every time.
What if a stage has two inputs?
Some stages buy more than one thing. Add the input costs first, then subtract once.
Suppose a packaging stage sells at RM900 and buys cartons at RM100 and film at RM50. Inputs are RM150, so value added is 900 − 150 = RM750.
Then ask whether the data is complete. If a cost is missing, say the value added cannot be found. The graph evidence and fair-comparison lab helps you practise this kind of check.
Check yourself
A tin chain: miners sell ore for RM400 (no inputs). A smelter buys it and sells metal at RM1 000. A maker buys the metal and sells cans at RM1 500. Find value added at each stage and the final price check.
Answer
Miners: RM400 − 0 = RM400. Smelter: RM1 000 − RM400 = RM600. Maker: RM1 500 − RM1 000 = RM500.
Sum: 400 + 600 + 500 = RM1 500, which matches the final price. The smelter adds the most value.
What to study next
Next, read explaining the location of an activity from several stated factors. For a teacher to check your calculations on new chains, see online one-to-one Geography tuition.