Then the bank or broker will use the amount to divide by the unit price to give you the unit. So the unit price will go up and down everyday and depends when you sell it, and you make money out of it based on the difference between the unit price you bought the funds, and the current unit price. In mutual fund, you can hold 0.5 or 0.1 units, which is different than stock. You have to keep this on mind. Thus you can buy something like 1000 or 3000 dollars regardless of the unit price. But the price of fund is still depends on the unit price.
Then there comes dividend (with exception of few mutual funds which don't give dividends), some are annually, some are semi-annually, some are quarterly. And they normally give you dividend as a form of more units. Suppose on the dividend day, the unit price is 10, and they calculated that you get $400 as dividend, they just give you 40 units more in your porfolio.