How many nines? There are 20 nines between 0 and 100. One in each unit digit (9,19,29,39,… 99), plus the ten nines of decade 9 (90, 91,92… 99). In total 10 + 10 = 20 nines. Back to statement Challenge 33 How to cross the river? Challenge Index Next >> Challenge 35 The Price of the Gift

What is root settlement? We already know that 6² = 36. We will now learn the operation that allows us to determine which number squared equals 36. because 6 squared is 36. This operation is the inverse of potentiation and is called root. Other examples: because 2³ = 8., because.

A vector determined by an AB oriented segment is the set of all AB-oriented segments. If we indicate with this set, symbolically we can write: = {XY / XY ~ AB} where XY is any segment of the set. The vector determined by AB is indicated by either B - A or.