Remember that you have to break the circuit and insert the ammeter in series with the 10V source to allow the current to flow through the ammeter.
(you; to break; the circuit) (you; to insert; the ammeter; in series with the 10V source; to allow the current to flow through the ammeter)
you you
to break to insert
the circuit
the ammeter in series with the 10V source to allow the current to flow through the ammeter