In our example two zinc acid cells in series would give an EMF of 1.52 V. 10 of them would provide 7.6 volts. You can think about these by analogy to the flow of water in a waterfall. With a tall waterfall, each drop hits very hard when it hits the bottom. With a short waterfall, the drops don't hit very hard. This is analogous to voltage.
Some waterfalls have a lot of water flowing, others only a little.
This is analogous to current. Current is defined as the rate at which electrons flow from anode to cathode. Consider a very tall waterfall with very little water flowing over it. If you stand under such a waterfall, each water drop will hit you pretty hard. They may even sting you a little.