diff --git a/hw4-pybind/README.md b/hw4-pybind/README.md
index a191c29e..91f7933d 100644
--- a/hw4-pybind/README.md
+++ b/hw4-pybind/README.md
@@ -1,12 +1,16 @@
 
 # Homework 4
 
 ### Exercise 4:
 Can run the example using the command `./particles 365 1 ../init.csv planet 1` from the `build` folder. From C++ the gravitational constant G must be changed accordingly.
 
 The trajectories can be viewed using Paraview, and we observe trajectories as expected. Except for Mercury.
 
-### Exercise 5:
+### Exercise 5 through 7:
 See the file `python_functions.py`.
-Note that we assume 5 integers in the filenames (not 4 as in the trajectory folder).
+Run the file from the `build` folder with `python3 ../python_functions.py`.    
+
+Note that we assume 5 integers in the filenames (e.g. `step-00000.csv`), i.e., not 4 as in the trajectory folder.
 We can easily rename multiple files using the command `rename 's/step-0/step-00/g' *` in order to get same naming convention.
+
+We find that the scaling factor for Mercury's velocity is approximately 0.4.