IGCSE CASE matches one value. 9618 adds inclusive ranges, which is how grade boundaries are written.
Read an integer mark from 0 to 100. Output the grade:
- 80 TO 100 →
A
- 60 TO 79 →
B
- 40 TO 59 →
C
- anything else →
U
80 TO 100 includes both ends.
Write `80 TO 100 :` with the colon. A chain of IF is not what this question is practising.