2K2 Example...

2K2 +/- 5% = 2090-2310R

oh... 2310R... is that a 2K4 (+/-5%) Resistor?

and... 2090R... is that a 2K0 (+/-5%) Resistor?

Your students have now sorted all your Resistors into their respective bins. Next lesson, a student dips his hand into the 2K0 Resistor bin and pulls one out marked Red-Red-Red. Now, is it a Resistor that's been put into the wrong bin, or a really poor 2K2 that's closer to 2K0? Does he then learn from his experience that Red-Red-Red means 2K0?

I don't think you could encompass the entire Resistor selection, but certainly the basic 82/84 (12 step) range (1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2).