Geometry:

https://www.youtube.com/watch?v=NVuMULQjb3o
https://www.youtube.com/watch?v=2JSk0DC5q4g





Naming the angle:

There are many ways to name the angle:




Most common way:
Right ray, Vertex, left ray. So this angle we can call AOB.

We can also call this angle only O.

Name these angles:




Properties of multiplication.

Write to your notebook:
Examples:
- several negative integers multiplied (what is the rule?)
- Commutative property (a.b = b.a) 
- Associative property (a.b) . c = a. (b.c) This can make calculating easy! 13 . (-5) . (-2)
- Distributive property a(b+c) = ab + ac. Calculations in two different way. 4 . (8-6)