An effective way to do statistics

I am  very proud that my grandson learned today to use saw workers statistical method.  You can count easily mark big amounts of units by this method.  First you make four corners, then four walls and then two sticks for rafters, altogether 10 units.  When you make statistics outside with paper and pen, you can easily mark big amount of units by this method and  you can quickly count the amounts when you know that in one "house" there are ten units.
  I am proud that we had fun with my grandson to make these "houses".  I have taught this method for thousands of students of psychology on statistical courses, but never before for a student who is  5 years old.  My grandson tells that earlier Akku had hundreds of students and now only one.  Nowadays when I am retired and I have only this one student, my topics of teaching are much wider than earlier.  I have had to learn about dinosaurs, slime molds and many other stuffs that I did not know earlier. Important is that we have fun so often as possible whatever we do.