Introduction:
The teacher reads the students the following rhyme :

ON TWO RED SOFAS
THERE ARE TWO CATS
THAT EACH HAVE TWO PAIRS OF WHISKERS.
ON EACH PAIRS OF WHISKERS, THERE ARE TWO FLIES…
HOW MANY FLIES ARE ON CATS
THAT ARE ON RED SOFAS?

The teacher asks the students to represent the rhyme with a graph using signs and numbers.

Main part:
Pupils give a different color to each element of rhyme and place it following the directions

Roundup:
Each element is multiplied by two and the result is as follows :

The teacher concludes that this chain of multiplications can be abbreviated as