The two written long-division layouts are incomplete.
a) For \(7843\div25\), find the missing final quotient digit and the missing final subtrahend. Then state the quotient and remainder.
b) For \(15{,}000\div37\), find the missing middle quotient digit. Explain why that digit must be written even though the corresponding subtrahend is \(0\). Then state the quotient and remainder.
Check both results with multiplication.

Hints
- Follow each displayed partial dividend to the next quotient digit.
- In a), the final quotient digit is determined by the displayed partial dividend \(93\).
- In b), compare the middle partial dividend with the divisor before deciding whether a quotient digit can be omitted.
Solution
1. In a), after \(78-75=3\), bring down \(4\) to get \(34\). Subtract \(25\), leaving \(9\), and bring down \(3\) to get \(93\). Since \(25\times3=75\), the missing quotient digit is \(3\) and the final subtrahend is \(75\). The result is \(313\text{ R }18\).
2. In b), \(150-148=2\). Bringing down the next \(0\) gives \(20\), which is smaller than \(37\), so the tens quotient digit is \(0\) and the subtrahend is \(0\). Bringing down the last \(0\) gives \(200\), and \(37\times5=185\), leaving \(15\). The result is \(405\text{ R }15\).
3. Checks: \(313\times25+18=7843\) and \(405\times37+15=15{,}000\).
Answer
a) Missing quotient digit: \(3\); missing subtrahend: \(75\); \(7843\div25=313\text{ R }18\), because \(25\times3=75\) is the greatest multiple of \(25\) not exceeding the displayed \(93\).
b) Missing middle quotient digit: \(0\); \(15{,}000\div37=405\text{ R }15\). The \(0\) must be written because the displayed partial dividend \(20<37\), preserving the tens place.
Checks: \(313\times25+18=7843\) and \(405\times37+15=15{,}000\).