# Understanding formulas involving divison and multiplication

1. Jun 1, 2014

### Niaboc67

I've never quite understood is how formula can involve division and multiplication while dealing with abstract concepts. Such as, ohm's law V = I•R where V=voltage applied I=current and R=resistance. How does that work exactly? how can you multiply two abstract concepts together to understand the equivalence to something else. Is this to assume we are evaluating for something, correct? if we know the certain number of volts and the current we can figure out the voltage? if this is correct can this be reversed in order to figure out the others alone, such as I and R?

Other formulas such as Speed = distance / time. Things like these have always confused me, maybe I just don't quite understand division but how can diving possible given you the outcome of speed?
Also anything dealing with infinities and pi in formulas I don't see how these are work together to form an understanding.

2. Jun 1, 2014

### Nathanael

Many times it is a definition. Like (speed = distance / time), that's just the definition of speed. Mathematics is just a language and that is the mathematical translation of "speed is distance per time" or "speed is how long it takes to go a distance" or "speed is how far you go in an amount of time"
Those are 3 verbal (english) ways of defining speed. Division is just part of the language used in the mathematical definition.

As with any language, you have to use it quite a bit before you can understand it fluently. You have to use it a lot to understand the subtle meanings involved, and you also have to use it a lot before you can think with it.

3. Jun 1, 2014

### A.T.

How would you calculate speed instead?

4. Jun 1, 2014

### sophiecentaur

Speed is a 'concept'. You can't avoid the Maths.

5. Jun 1, 2014

### SteamKing

Staff Emeritus