Learn

Learning preferences

Make learning more comfortable. Changes apply immediately.

Enlarges page content, including diagrams and their labels. You can also use your browser’s zoom.

Choose the colours that are easiest for you to distinguish. Applies to lesson diagrams and lab plots. Labels, shapes, hatching and line patterns also distinguish meanings. Source photographs and raw image brightness stay unchanged; mask-only views are available for image overlays.

ExampleComparisonSample link

Saved in this browser on this device. Preferences are separate from progress backups.

Learn through experiments

Scale a fraction without losing the whole

What stays the same when a reference batch changes?

Entering midway? Division asks how many equal parts or how much per part. A ratio compares quantities; percent means per hundred.

1 · Try

Start with a concrete question

Use an original synthetic batch calculation to connect a fraction, decimal, percentage and amount. All units are litres.

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 prerequisite mathematics and return here

2 · Predict

What do you expect?

Predict whether doubling the reference batch changes the fraction or only the amount.

3 · Experiment

Change one thing. Inspect what happens.

  1. At 3/4 of 12 litres, predict the amount before checking.
  2. Use 6/8 with the same batch. Explain equivalent fractions.
  3. Try numerator larger than denominator and interpret an amount above the reference.
Experiment inputs
Inputs
Your settings
Mechanism
Calculation below
Evidence
Compare outcomes
Fraction as decimal0.75
Percentage75 %
Scaled amount9 litres

Same ratio at different reference sizes

Horizontal: Reference batch (litres). Vertical: Scaled amount (litres).

002012040240Constant ratio: (0, 0)Constant ratio: (40, 30)Your batch: (12, 9)
  • 1. Constant ratio (solid line)
  • 2. Your batch (points)

Axes use the displayed ranges.

Read plotted values as a table
SeriesReference batch (litres)Scaled amount (litres)
Constant ratio00
Constant ratio4030
Your batch129

Follow the calculation

  1. Fraction 3/4: divide 3 by 4 = 0.75.
  2. Percent means per hundred: 0.75 × 100 = 75%.
  3. Apply to a 12-litre reference batch: 12 × 3/4 = 9 litres.

A fraction names a ratio, not an absolute amount. Values above one represent more than the reference whole.

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

Scale a fraction without losing the whole

Recap for entering here

Division asks how many equal parts or how much per part. A ratio compares quantities; percent means per hundred.

The concrete question

Use an original synthetic batch calculation to connect a fraction, decimal, percentage and amount. All units are litres.

Predict whether doubling the reference batch changes the fraction or only the amount.

Work through the mechanism

The denominator names the number of equal parts; the numerator counts those parts. Three quarters means three of four equal parts.

3/4 = 0.75 = 75%. Applied to 12 litres, each quarter is 3 litres, and three quarters total 9.

The ratio is a slope on the batch graph: every extra reference litre adds 0.75 scaled litres at this setting.

Formula and symbols

Fraction r = numerator/denominator; percentage = 100r; amount A = rB where B is reference litres and A is scaled litres.

Test the idea

  1. At 3/4 of 12 litres, predict the amount before checking.

  2. Use 6/8 with the same batch. Explain equivalent fractions.

  3. Try numerator larger than denominator and interpret an amount above the reference.

Assumptions and boundaries

  • The denominator is positive; ratios with zero denominators are undefined.

  • A fraction above one is mathematically valid but may be infeasible for a fixed physical container.

Extend your investigation

High school: Scale an invented recipe and label every quantity.

College: Prove equivalent ratios by multiplying numerator and denominator by the same nonzero value.

Working professionals: Audit a percentage dashboard for changing denominators.

5 · Apply

Try a fresh case

What is 5/8 of a 24-litre reference batch?

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

Scale an invented recipe and label every quantity.

College investigation

Prove equivalent ratios by multiplying numerator and denominator by the same nonzero value.

Workplace investigation

Audit a percentage dashboard for changing denominators.

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.