Matrices

A real board, not a video.

This board is from a different Maths lesson — yours will look like this. She writes and draws while she explains, and stops to check you followed.

Doubts this lesson clears up

• Why do we use matrix notation instead of just calling it a table? What's the power?
• Why can't we multiply matrices in any order like we do with ordinary numbers?
• How do I know whether I'm allowed to multiply two matrices before I start?
• Why would anyone flip a matrix around? Where would you actually use a transpose?
• What does it mean for a matrix to be 'symmetric'? Can you show me a real-world example?
• How are the spreadsheets I use every day actually matrices under the hood?