Here are some key terms for this topic: Key Terms C4

IGCSE Chemistry: Topic 4 Stoichiometry, a series of 9 lessons from Sal Sciab.

IGCSE Chemistry: Basic Calculations, a 15m lesson from ChemistryKlipz (some of which we don’t need for the exam).

2 videos on Stoichiometry which probably go into too much detail but are very good – Hank Green from Crash Course Chemistry talks very fast & Salman Khan does not.

A good powerpoint that covers most of what you need but misses out calculations for gases and solutions: