To solve these conversions, we need to remember the following equivalences:

1 m^3 = 1000 dm^3
1 dm^3 = 1000 cm^3

Now let's solve each conversion:

1) 5 m^3 = 5 * 1000 dm^3 = 5000 dm^3

2) 1996 dm^3 = 1996 * 1 m^3 = 1996 m^3

3) 4 dm^3 + 97 cm^3 = 4 dm^3 + 97/1000 dm^3 = 4.097 dm^3

4) 5 dm^3 + 39 cm^3 = 5 dm^3 + 39/1000 dm^3 = 5.039 dm^3