diff --git a/ToDo.md b/ToDo.md
index 7d215aa..683718a 100644
--- a/ToDo.md
+++ b/ToDo.md
@@ -1,8 +1,8 @@
 ## Known problems to be fixed
 
 - [ ] *Plot3DSys* function has issues when the matrix has a rows made of all zeros
 - [ ] Exercise 4 in Notebook 1.2 displays a *RuntimeWarningError* due to a division by 0, 
-      if the "sliging" parameter *h* is set to 0
+      if the "sliding" parameter *h* is set to 0
 - [ ] *printA* library method fails if it is given a row vector (i.e. a list of int/float)
       as input
 - [ ] *ipywidgets* have troubles being displayed on **Noto**