Use this phrase to talk about a number which is very high or very low, but which you don't know exactly:
They say it's going to get up to something crazy like 102 degrees this week!
The distance to the nearest star is something crazy like 40 million million miles.
His commute to work used to be something crazy like two and a half hours.
In general, "crazy" can describe something that's surprising:
That is crazy expensive!
I found a crazy number of mistakes in my earlier calculations.