CALCULATING TOTAL CURRENT

The total current in a parallel circuit is the sum of the currents in all the branches

I.t = I1 + I2 + In + ....

Therefore to calculate the current in a kit, the meter probes must be close the the positive polatity of the voltage source, then the circuit must be "broken" and the meter is placed in series with the circuit, with the voltage source connected.

CURRENT CONSUMPTION

Current consumption is the current used to operate a device.  Take for example a LED which uses 20mA.  If you have a 5volt battery, and the voltage drop over a LED is 2volts and you wanted to connect 2 LEDS to the circuit, the total current consumed would be 20mA, and the total voltage is 4 volts.  

If you wanted to connect 4 LEDs, then a parallel circuit would be needed, each have a 20mA path.  Then the total current drawn would be 40mA, with the voltage the same across the two branches, in this case 5 Volts in each branch, hence each LED can have the 2 volts to operate.