Task 1
$5,000 x 1.04 = $5,200.
Teacher guide
Measure what savings can buy
Students compare a 4 percent nominal return with 3 percent inflation, calculate the exact real return, and explain why a larger statement balance need not mean 4 percent more purchasing power.
Time
30 minutes
National topic
III. Saving
Selected outcome
Saving 12-4b
Separate student view
Share or print the student handout
The student page contains the scenario, resource links, prompts, response space, and privacy boundary. It does not contain this teacher key.
Complete teacher packet
Download one printable file with preparation, the fictional scenario, checked resources, all tasks, the teacher key, evidence check, extension, and LMS post. Keep it teacher-only because it contains answers.
Download teacher packetReady-to-paste class post
The post includes the exact handout, time, goal, directions, and privacy boundary.
Objective and outcome
Distinguish a nominal account balance from its value in today's dollars.
Saving 12-4b: Show how inflation can reduce the purchasing power of savings. This is an independent selective correlation. Use the standards crosswalk for the source and claim boundary.
Teacher preparation
- Open the real return calculator and set years to one.
- Share or print the student handout.
- Remind students that the rates are fictional and the task compares arithmetic, not products.
Fictional scenario
A fictional saver holds $5,000 for one year at a 4 percent effective annual return while prices rise by 3 percent.
Checked resources
- Real return calculator
Students compare nominal and inflation-adjusted balances.
- Nominal and real return comparison
Students repair the subtraction shortcut.
- Inflation eroder
Students test a second inflation path.
Student task sequence
- Calculate the statement balance after one year at 4 percent before opening the calculator.
- Enter 4 percent return, 3 percent inflation, $5,000, and one year. Record the exact real return and the balance in today's dollars.
- Compare the exact real return with the 1 percentage point subtraction shortcut.
- Explain in one sentence why $5,200 on the statement does not buy 4 percent more goods when prices also rise.
- Raise inflation to 5 percent, keep every other input fixed, and describe the sign of the real return.
Teacher key
Task 2
The exact real return is about 0.97 percent and the balance in today's dollars is about $5,048.54.
Task 3
Simple subtraction gives 1.00 percent, which is about 0.03 percentage points too high.
Task 4
Purchasing power depends on the ratio of account growth to price growth, not the statement balance alone.
Task 5
The real return becomes negative because prices rise faster than the account.
Four-point evidence check
Award one point for each visible item.
- The nominal balance and real balance are both recorded.
- The exact ratio is distinguished from subtraction.
- The explanation uses purchasing power rather than only account value.
- The higher-inflation test correctly identifies a negative real return.
Extension
Test a ten-year holding period and explain why the nominal and real dollar balances separate more over time.
Browse the other classroom lessons or build a focused set from the teacher toolkit.
This page is educational material, not financial advice. The figures come from the formula shown and assume the inputs you enter hold for the whole term. Your own rate, fees, taxes and timing will differ, so treat the output as arithmetic to check a decision against, not as a recommendation.