1. **State the problem:** We have a vertical addition with unknown digits $a$, $b$, and $c$: 5 3 2 $a$ 9 + 7 4 2 $b$ = $c$ 0 6 7 6 We need to find the digits $a$, $b$, and $c$ that satisfy this addition. 2. **Analyze the units column:** Units column: $9 + b = 6$ or $9 + b = 16$ (if there is a carry of 1) - If $9 + b = 6$, then $b = -3$ (impossible). - So, $9 + b = 16$ with a carry of 1 to the tens column. Therefore, $b = 7$. 3. **Tens column:** Digits: $a + 2 + 1$ (carry from units) = 7 or 17 (if carry to next column) - If sum is 7, then $a + 3 = 7 ightarrow a = 4$ with no carry. - If sum is 17, then $a + 3 = 17 ightarrow a = 14$ (impossible). So, $a = 4$ and no carry to the hundreds column. 4. **Hundreds column:** Digits: $2 + 4 + 0$ (no carry) = 6 Sum is 6, no carry. 5. **Thousands column:** Digits: $3 + 7 + 0$ (no carry) = 10 Sum is 10, so digit is 0 and carry 1 to the ten-thousands column. 6. **Ten-thousands column:** Digits: $5 + 0 + 1$ (carry) = 6 Sum is 6, so $c = 6$. 7. **Final check:** 5 3 2 4 9 + 7 4 2 7 = 6 0 6 7 6 Calculate sum: $53249 + 7427 = 60676$ This matches the sum given. **Answer:** $a=4$, $b=7$, $c=6$