6 converters. Webers, milliwebers, microwebers and maxwells, each with the formula and the math worked out with your numbers.
0.001 Wb = 100,000 Mx
100,000 Mx = 0.001 Wb
250 mWb = 0.25 Wb
0.5 Wb = 500 mWb
10 µWb = 1,000 Mx
5,000 Mx = 50 µWb