I am currently doing a Future Learn course called Electrify. It is an introduction to Electrical and Electronic Engineering.
In week 2 we looked at Resistors so my husband was delighted to get out his boxes and tins of resistors to show me.
We did a little exercise to identify some of his collection. I used the colour chart link given on the course, plus a magnifying eyepiece as the little ones are mighty difficult to see.
We then measured the actual resistance of each resistor on an electric meter.
This highlighted the tolerance from the calculated measurement gained from the colour bands.