To split a chip double click on it. Or hold down the shift key and then use a single click.
You will bring up the split chip dialog box.

You can change either value. The easy way is to select the 2nd box, use a double click so it's all selected then enter the new number. ( like 10 for $10.00 ). I always split my chips based on their new value. You can change the default of which number is selected when this dialog appears by using the "chip pref" option under the EDIT menu.

To move a chip simply put the cursor over a chip then press the mouse button and drag it to a new location. If the new chip will touch another chip they will be combined into a single chip with a value of the sum of the two chips.