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Learn through experiments

Allocate a constrained budget

Which combinations fit after reserving a safety margin?

Entering midway? Revisit Does twice the speed mean half the journey? for the preceding worked example, or start here and use the explanation below.

1 · Try

Start with a concrete question

An original synthetic project buys A units for 4 credits and B units for 6. Choose a reserve and A quantity, then calculate the maximum whole B quantity.

Try the initial inputs, then write a prediction before changing one setting. All calculations run locally on your CPU.

Go directly to the experiment · Review basic mathematics

2 · Predict

What do you expect?

Predict how one extra A changes the feasible B count.

3 · Experiment

Change one thing. Inspect what happens.

  1. At default settings calculate remaining funds before B.
  2. Increase A one unit at a time and explain the staircase in whole B units.
  3. Choose an infeasible A/reserve pair; explain why zero B does not make it feasible.
Experiment inputs
Inputs
Your settings
Mechanism
Calculation below
Evidence
Compare outcomes
Affordable B units6
Spending on A and B76 credits
Over budget including reserve0 credits
Unallocated credits4 credits

Compare the current results

Every bar starts at zero and uses the same numeric scale in this chart. The upper bound automatically adjusts to the largest current value (at least 1), so compare the numbers when changing inputs. Units and quantities come from each label; different kinds of quantity are not interchangeable. Displayed values are rounded to at most six significant digits.
040
  • Reserve credits20
    Reserve credits: 20Horizontal bar from zero to 20, on the shared zero to 40 numeric axis.
  • A cost credits40
    A cost credits: 40Horizontal bar from zero to 40, on the shared zero to 40 numeric axis.
  • B cost credits36
    B cost credits: 36Horizontal bar from zero to 36, on the shared zero to 40 numeric axis.

Follow the calculation

  1. Budget 100 − reserve 20 − 10 A units × 4 = 40 credits for B.
  2. Each B costs 6; whole affordable units = max(0, floor(40/6)) = 6.
  3. Total committed = 20 + 40 + 36 = 96.

A constraint defines feasible choices. More of one item reduces room for another; negative availability signals an infeasible A/reserve choice.

Captures keep your inputs, prediction and observation. Results are recalculated from those inputs. Resetting inputs keeps your captures and challenge history.

4 · Understand

Explain the mechanism

Allocate a constrained budget

An original synthetic project buys A units for 4 credits and B units for 6. Choose a reserve and A quantity, then calculate the maximum whole B quantity.

Predict before changing inputs

Predict how one extra A changes the feasible B count.

Understand the mechanism

A constraint is a rule every allowed choice must satisfy. Here 4A + 6B + reserve ≤ budget.

With 100 credits, 20 reserved and 10 A units, 40 remain. Six B units cost 36 and leave 4 credits.

Floor means the greatest whole number no larger than a value. You cannot buy 6.67 indivisible items.

Calculate it yourself

B = max(0, floor((budget − reserve − 4A)/6)), with feasibility checked separately.

Guided investigation

  1. At default settings calculate remaining funds before B.

  2. Increase A one unit at a time and explain the staircase in whole B units.

  3. Choose an infeasible A/reserve pair; explain why zero B does not make it feasible.

Assumptions and limitations

  • Prices and quantities are fixed assumptions; no bulk discounts or utility ranking.

  • Feasible does not mean best: the value of each item is not modeled.

Further investigations

High school: Plan a fictional school event with an explicit contingency reserve.

College: Enumerate feasible integer choices and optimize a stated utility.

Working professionals: Document a resource-allocation decision and its sensitivity to cost changes.

5 · Apply

Try a fresh case

Budget 90, reserve 10, and 8 A units at 4 each: how many whole B units at 6 fit?

This is a public practice check. Retries support learning; matching a number does not certify independent proficiency.

Take the investigation further

Choose any extension. These are project prompts for you to carry out; they are not automatically assessed.

School investigation

Plan a fictional school event with an explicit contingency reserve.

College investigation

Enumerate feasible integer choices and optimize a stated utility.

Workplace investigation

Document a resource-allocation decision and its sensitivity to cost changes.

6 · Continue

Keep the evidence, choose your next step

Completion records your own decision that you have worked through this investigation. Practice checks and independent project evidence are separate.