5. (5 points) Fill in the eight boxes below with the numbers $2,3,4,5,6,7,8,9$ (without repetition) to form many different subtraction expressions. To make the calculation result the smallest and a natural number, then this calculation result is . $\qquad$

Fill in the eight boxes below with the numbers $2,3,4,5,6,7,8,9$ (without repetition) to form many different subtraction expressions. To make the calculation result the smallest and a natural number, then this calculation result is . $\qquad$
【Answer】Solution: $6234-5987=247$. Therefore, the answer is: 247 .