Lay the multimeter and the two prongs, or leads, on a flat surface and note that each is made of a probe that is attached to a plug. Hold the plug at the other end of the lead and note that it is the part that connects to the multimeter.
Hold the multimeter and see the slots located just below the dial or screen; the slots are female plugs that accommodate the male plugs at the other end of the leads. Note that each slot is marked by a positive and negative sign.
Connect the leads to the multimeter by inserting each plug into its corresponding slot, but be sure to connect the positive (red) lead to the positive slot and the negative (black) lead to the negative slot. Turn on the multimeter and use it to test a circuit.