TRY · PREDICT · EXPLAIN
Four small practice activities: combine objects, add matrix entries, trace a program and inspect a model’s predictions.
These sample exercises work immediately and use no AI calls. Answers are temporary and do not count toward saved course progress. More subject-specific interactive laboratories are planned; course practice is currently delivered through the existing activity system.
A pencil box holds the outlined group. Add the filled group. How many pencils are there altogether?
Count each object once. Combining the groups gives 5. Changing the order leaves the same total; adding zero leaves the original group unchanged.
Rows are two shops; columns are pens and notebooks. Add a delivery to the current stock. Find shop 2’s new pen count: row 2, column 1.
Delivery matrix: row 1 is 1, 2; row 2 is 5, 3.
Add matching positions: 3 + 5 = 8. The full result has rows (3, 6) and (8, 4). Matrix addition needs equal dimensions.
A receipt totals three item prices. Follow the value of total after each iteration. This is a fixed code-reading exercise; no code runs here.
total = 0
for price in [2, 3, 4]:
total = total + price
print(total)The state changes from 0 to 2, then 5, then 9. The print instruction runs once after the loop. Check indentation before predicting output.
A toy fruit-image model labels 10 images “apple”. Eight actually show apples; two show pears. Precision asks how many predicted apples were correct.
Correct apple predictions: 8. All apple predictions: 10.
Precision = 8 ÷ 10 × 100 = 80%. This does not tell us recall: we also need the number of actual apples the model missed.