# How do I determine what range (not necessarily value) of resistors to use for voltage dividing [duplicate]

I'm getting back into electronics as a hobby and doing some refreshers having been away from it for a long time. I understand Ohm's law and voltage dividing, however, I'm not sure I understand what the proper ranges of resistors to use are when dividing voltages.

For example, if I have a 5 V source and I want two 2.5 V divisions, I can use two 10 kΩ resistors to get that.

But I can ALSO use two 100 kΩ resistors, or two 1 MΩ resistors. What I'm struggling with is: what is the determining factor or calculation that I should be using to determine which pair is the best way to do this? Is it based on current requirements?

On a side/similar note, as a project I'm going to build a digital thermometer. I have a TM346 sensor and will be converting its output to digital and use a microprocessor to convert to a temperature, but to use the A/D converter (ADC0804LCN) and get the full dynamic range of conversion, I need to supply this chip some reference voltages.

What's the best way to provide accurate voltages to this chip? I figure voltage dividing is not the best way to handle it. Aa a low reference I need to supply 322 mV and as a high reference I need to supply 628 mV. I'm assuming voltage dividing is NOT the best way to accurately get these values.