Percent Bar-Model Lab
Shade the hundred-grid, stretch the bar model, and run the famous “raise 10%, then cut 10%” experiment. Discover that percent is a relationship, not an amount.
1 Explore Percents Visually
Move the sliders and watch the pictures change. Percent is a relationship between a part and a whole.
Hundred-grid
Slide past 100% — the grid caps at 100 shaded squares, but the bar model below keeps going.
Bar model: p% of N
Same percent, different whole: the percent stays 25%, but the amount changes with N.
Experiment: raise 10%, then cut 10%
Predict the final price first (below), then run the experiment.
Start
After +10%
After −10%
2 Benchmark Paths to 45% of 200
Three different ways to reach the same answer — pick the path that feels easiest.
3 Challenges
Set the sliders, then press Check.