Without calculating, is the equation (1.8 times 3) times 2.1 = ( 1.8 times 2.1 ) true or false? explain your reasoning.

It is true due to the commutative property of multiplication. If all of your operations are multiplication, then the integers can move around and you can still get the same answer. 
^This is only true if you meant to type (1.8x3)x2.1=(1.8x2.1)x3

If you meant what you typed, then the equation is false. The left side would be 3 times the value of the right side due to the 3 being on the left side and not the right side while without the 3 the two sides would be equal.