For what measurements? if you’re talking like science stuff i use King Henry Drank My Delicious Chocolate Milk for Kilo Hecto Decka, middle, Deci, Centi, Milli. middle is your unit!
D= (12)/(3)(4)
d = 12/12
d = 1
The answer is given above
It is 9 degrees because at 6am the temperature was -12 degrees and at 10am the temperature was -3 degrees.