The unit digit of2543 is 5. The unit digit of 5642 is 6. The unit digit of 45625 is 6. The unit digit of 2342 is 9. The unit digit of 7623 is 6. ∴ The resultant value of the unit digits = [(5 × 6) + 6 + 9 + 6] = (30 + 6 + 9 + 6) = 51 So, the unit digit of the expression is 1.