Find closest multiple of $42$ to $65$. We see that $1 \times 42 = 42$ is the nearest. Now subtract $42$ from $65$ to get reminder $23$. Add $1$ to quotient.
Find closest multiple of $42$ to $234$. We see that $5 \times 42 = 210$ is the nearest. Now subtract $210$ from $234$ to get reminder $24$. Add $5$ to quotient.
Since $24$ is less than $42$, stop the division. The reminder is $24$. The topmost line $015$ is the quotient. Remove all zeros at the start of the quotient to get the actual quotient $15$.