Setting Two Cargoes Equal
A 55-minute Grade 5 lesson on how money makes unlike goods comparable, using a treaty that says 'to the same value'.
Setting Two Cargoes Equal is a free 55-minute Grade 3 to Grade 5 social studies lesson plan for Common Core standard D2.Eco.5.3-5 — explain what money does that swapping goods cannot. It is timed across 5 sections, gives the exact wording to use where the wording carries the mathematics, names 3 misconceptions with the teaching move that addresses each, and ends with an exit ticket and a printable worksheet with its answer key.
- Grade:
- Grade 3 to Grade 5
- Length:
- 55 minutes
- Standard:
- D2.Eco.5.3-5
Grade 3 to Grade 5 · Economics
D2.Eco.5.3-5
Explain the role of money in making exchange easier.
Objective
Students will be able to explain what money does that a direct exchange of goods cannot.
Students are successful when they can
- Explains how money makes unlike goods comparable.
- Explains why the exchange still needs a shared measure.
- Says why money can be committed over years.
What you need
- The trade agreement's phrase 'to the same value'
- The white paper on taxation and borrowing
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up — how much timber is a lathe?
5 min- Ask how many tons of timber equal one machine tool.
- Let the class find they cannot answer without a price.
Teach — measure, commit, defer
18 min- Read 'to the same value'. Money is what makes that phrase mean anything.
- Job one: it measures two unlike goods in the same unit.
- Job two: it lets a commitment be made for five years, because the measure holds.
- Job three: it lets a government spend now and repay later, from the white paper.
- Ask what a barter treaty would have had to say instead. Tons for units, renegotiated constantly.
- Ask what money needs to work here: both governments accepting the same measure.
- Take the limit: a total in pounds says nothing about who bore the cost.
“Which job of money is doing the work in this sentence?”
Guided practice — name the job
17 min- Pairs take eight statements from the sources and name money's job in each.
- They find one statement doing two jobs.
- Groups write a barter version of one clause and see what it costs.
Independent practice
12 min- Students complete the 'Setting Two Cargoes Equal' page.
- Check answers name a job rather than saying money is easier.
Close
3 min- Ask which job of money the white paper depends on most.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Says money is better because it is portable.
Why: Carrying is the obvious advantage.
Fix: No coins crossed here. The work was done by the measure, not the metal.
Thinks money has value in itself.
Why: It buys things.
Fix: It works because both governments accept the same measure. Ask what happens if one stops.
Thinks a money total tells the whole story.
Why: Numbers look complete.
Fix: The programme's cost in pounds says nothing about the family waiting seven years.
If they are not there yet
- Four statements and two jobs.
- Rewrite one clause as a swap and see what breaks.
If they finish early
- Say what happens to 'the same value' if one currency falls.
- Explain why a five-year commitment needs a stable measure.
- Find a case where money measured something badly.
Exit ticket
The agreement says machine tools 'to the same value' as the timber. What is money doing there?
What to look for: Measuring two unlike goods in one unit so an equal exchange can be agreed. Answers about coins being convenient miss the job.
Printable practice for D2.Eco.5.3-5
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- Setting Two Cargoes EqualCircle the best answer.
Questions about Setting Two Cargoes Equal
How long does the Setting Two Cargoes Equal lesson take?
55 minutes, split across 5 timed sections: warm-up 5 min, teach 18 min, guided practice 17 min, independent practice 12 min, close 3 min. The minutes are stated per section and add up to the stated length, so the plan can be cut or extended at a section boundary rather than abandoned halfway.
Which standard does Setting Two Cargoes Equal teach?
D2.Eco.5.3-5 — D2.Eco.5.3-5, Economics for Grade 3 to Grade 5: “Explain the role of money in making exchange easier.” In plain terms, explain what money does that swapping goods cannot.
What do I need to teach this lesson?
The trade agreement's phrase 'to the same value', the white paper on taxation and borrowing and the printable practice sheet linked at the end of this plan. Everything listed is either ordinary classroom equipment or a free printable from this site — there is nothing to buy and nothing to prepare beyond photocopying.
What mistakes should I expect in this lesson?
Three, each a reasoning error rather than carelessness: says money is better because it is portable; thinks money has value in itself and thinks a money total tells the whole story. The plan gives the thinking behind each one and the teaching move that addresses the thinking rather than the symptom.
How do I know whether the lesson worked?
The exit ticket asks: “The agreement says machine tools 'to the same value' as the timber. What is money doing there?.” Measuring two unlike goods in one unit so an equal exchange can be agreed. Answers about coins being convenient miss the job. That tells you whether the class needs a reteach or a thirty-second conversation before you plan tomorrow.
Is there a worksheet to go with Setting Two Cargoes Equal?
Yes — 1 printable D2.Eco.5.3-5 worksheet, linked at the end of the plan and free like the rest of the site. Each one comes with an answer key and 25 versions, so the practice after the lesson can be a different paper on every desk.
Is Setting Two Cargoes Equal free to use?
Yes. The plan, its printables and their answer keys are free to read, print and photocopy for your own class, with no account and no email capture. It was last reviewed on 7 September 2026. Please do not resell it or republish it as your own.
Last reviewed 2026-09-07. Aligned to D2.Eco.5.3-5 of the C3 Framework for Social Studies State Standards.