P1 · Applied mathematics · MEAS.TIME.BASIC

Time and duration basics

Intuition

Understand first, compress later.

Mathematical models translate real situations into quantities, relationships and assumptions.

Switch representations

Reading the clock3:40

hour hand — short and thickminute hand — long and thinhow far the hour hand has crept since the hour

The minute hand stands at 40 minutes, that is 40 · 6° = 240° past twelve. The hour hand does not sit on the 3: it travels 30° in an hour, so half a degree per minute — here 3 · 30° + 40 · 0.5° = 110°. That creep is what tells you at a glance whether the hour is nearly over.

Formal view

You can time and duration basics when you can recognise the underlying objects, select valid rules and check each step for equivalence or logical implication.

Why does it work?

This skill sits on a prerequisite network. If a step is unstable, repair the missing prerequisite instead of merely doing more items of the same type.