.5 is basically 1/2. We know this because .5 written as a fraction is 50/100 which you can simplify to 1/2.
6/10 is greater than 1/2. You can find this out by converting 1/2 to tenths. Multiply the numerator and the denominator by 5 to get 5/10. From there you can easily see that 6/10 > 5/10.
As for the number line simply use 10ths: 1/10, 2/10, 3/10 ... and input 6/10 and 5/10 in the appropriate areas.
You could do 0.9 1.6 3.5 dont know of thats what you ment but they all have decimals :)
P(8 or 12) = 1/6
P(not 8 or 12 = 5/6
Let the expected points fro one roll be X.

The answer is -(1/6) points.
(-10m^4n^7)(-3m^4n)
= -10*-3 m^4*m^4 * n^7* n^1
= 30m^8n^8