Between is used in connection with two persons or things: 'He divided the money between his two children.' Among is used for more than two: 'He divided the money among his three children.'

EXCEPTIONS:
If more than two are involved in a united situation, between is used: 'Between the four of us, we raised a thousand dollars.'

If a comparison or an opposition is involved, between is used: 'There was great rivalry between the three colleges. It was difficult to choose between them.'"