I have work this problem out

F< 1544.5
F= 9/5 C + 32
9/5 C + 32 < 1544.5
9/5 c + 32 -32 < 1544.5
9/5 C < 1544.5
5/9 * 9/5 C < 5/9 (1544.5)
Now my question to you is how do I rounded 1544.5 ?

Rond? C should be in five sig digits..

C<858.06