Please show stepwise how to perform these calculations

1) By dilution of the 100mg/L stock calcium solution, prepare five standards in (0, 0.1, 0.2, 0.3, 0.4, 0.5mg/L. (50mL).

i attemped using C1V1=C2V2 formula and am unsure if this is correct.

2) Using the 100mg/L stock magnesium solution provided, prepare an initial working standard of concentration 10mg/L and then five 50mL standard solutions (0, 0.1, 0.2, 0.3, 0.4 and 0.5mg/L)

Also attempted using C1V1=C2V2 but am unsure about my answers