The v1.0.0 reference lists fixed Calculator slots in Levels 5 and 6. Level 5 pairs it with Color Slider and the Slider hazard; Level 6 adds Cable and uses Pressure. These are guaranteed module families in that reference, not every possible appearance through random slots.
If a walkthrough labels this “Level 3 math,” compare its version and visible loadout before using it. The cited full-release Level 3 has Cable and Color Slider. A search phrase alone cannot establish that the other guide describes the demo.
For an interruption drill, pause an example immediately after the first entry. On return, require the caller to identify the stage and retain the original parity before reading the LED. Score a missing field separately from a wrong arithmetic answer.