Start Here — A Complete Tour

Checks — let the sheet prove itself

continues from lesson 3 — values defined earlier in the course stay live here

A check is a statement you claim is true. The engine evaluates it and shows a green tick when it holds, a red mark when it does not — so your worksheet can verify its own answers. Every green check in this tour is the engine confirming the lesson. To make one, add a cell and write a comparison (==, <, >) instead of an assignment.

leg_{a} = 3

leg_{b} = 4

hypotenuse = \sqrt{leg_{a}^{2} + leg_{b}^{2}}

5

Pythagoras

✓ pass

hypotenuse == 5

the classic 3-4-5 right triangle

Change leg_b to 12 (with leg_a 5) and the check goes red until the hypotenuse is 13 — checks are how you catch a number that drifted out from under you.