The Cost of Building on Credit
A 55-minute Grade 5 lesson on what an interest rate is and what it does to a programme funded by borrowing.
The Cost of Building on Credit is a free 55-minute Grade 3 to Grade 5 social studies lesson plan for Common Core standard D2.Eco.10.3-5 — explain what an interest rate is. 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.10.3-5
Grade 3 to Grade 5 · Economics
D2.Eco.10.3-5
Explain what interest rates are.
Objective
Students will be able to explain interest as a price and predict what a rate change does to a programme.
Students are successful when they can
- Identifies interest as the price of borrowing.
- Recognises interest received by a lender.
- Predicts the effect of a rate rise on a programme.
What you need
- The white paper's mention of borrowing
- Worked figures for a public loan
- The printable practice sheet linked at the end of this plan
The lesson
Warm-up — who pays for the borrowing?
5 min- The programme is funded partly by borrowing. Ask who repays it.
- Follow the answer to taxpayers, over years.
Teach — a price, both ways, and a programme
18 min- Name it: interest is the price of using somebody else's money.
- Show it both ways: the state pays it; bondholders receive it.
- Define the rate: the cost as a share of what was borrowed, so loans can be compared.
- Ask why a government is charged less than a company. It is more likely to repay.
- Now the programme: a rate rise makes every home more expensive to finance.
- Ask what that does to a target of 300,000. Fewer homes for the same money.
- Take the household case: borrowing rather than waiting seven years, and what that risks.
“Whose money is this, and what are they giving up while it is lent?”
Guided practice — six cases
17 min- Pairs decide who pays and who receives in six cases.
- For three they say whether the rate would be high or low, and why.
- Groups work out what a rate rise does to the programme.
Independent practice
12 min- Students complete the 'The Cost of Building on Credit' page.
- Check interest is named as a price, not a punishment.
Close
3 min- Ask why a government still borrows despite the interest.
What goes wrong, and why
Each of these is a reasoning error rather than carelessness. The fix addresses the reasoning.
Thinks a government borrows without cost.
Why: It can raise taxes.
Fix: Interest is paid, by taxpayers, over the years of repayment.
Thinks only borrowers meet interest.
Why: That is the memorable direction.
Fix: Bondholders receive it. Same idea, other side.
Thinks a higher rate means a greedier lender.
Why: Higher looks worse.
Fix: It usually prices risk, or the cost of money generally. Ask which.
If they are not there yet
- Three cases with the direction given.
- Work with one loan and one rate.
If they finish early
- Work out how many fewer homes a rate rise would fund.
- Say why borrowing suits a programme whose product lasts decades.
- Explain why a rate is a share rather than a fixed sum.
Exit ticket
Rates rise sharply while a housing programme is funded by borrowing. What follows?
What to look for: Each home costs more to finance, so fewer can be built for the same money. Answers about bricks miss the mechanism.
Printable practice for D2.Eco.10.3-5
Free to print and copy, answer key included. Each sheet can generate a fresh set of problems for a retake.
- The Cost of Building on CreditCircle the best answer.
Questions about The Cost of Building on Credit
How long does the The Cost of Building on Credit 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 The Cost of Building on Credit teach?
D2.Eco.10.3-5 — D2.Eco.10.3-5, Economics for Grade 3 to Grade 5: “Explain what interest rates are.” In plain terms, explain what an interest rate is.
What do I need to teach this lesson?
The white paper's mention of borrowing, worked figures for a public loan 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: thinks a government borrows without cost; thinks only borrowers meet interest and thinks a higher rate means a greedier lender. 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: “Rates rise sharply while a housing programme is funded by borrowing. What follows?.” Each home costs more to finance, so fewer can be built for the same money. Answers about bricks miss the mechanism. 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 The Cost of Building on Credit?
Yes — 1 printable D2.Eco.10.3-5 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 The Cost of Building on Credit 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.10.3-5 of the C3 Framework for Social Studies State Standards.