here's the way that i learned it:
convert them to mixed fractions and then go from there.
3.6 = 36/10 0.5 = 1/2
right now our problem looks like this: 36/10 ÷ 1/2 =
okay, so i learned the method keep it, switch it, flip it.
keep the first fraction in the equation, 36/10
switch the division sign to multiplication ÷ ⇒ ×
switch the numbers on the second fraction 1/2 ⇒ 2/1
okay, so our equation looks like this now:
36/10 x 2/1
okay, so now multiply across. (multiply the top numbers together and the bottom numbers together)
72/10
latly, we need to convert back to a decimal. divide the top number by the bottom one.
to do this, divide the top number by the bottom number
72/10
7.2
i hope this was helpful. this is how i learned dividing with decimals, so it might be kinda complicated. if you still need help, let me know :)