Count number of times a number appears

Which platform do you want to do this on? Could you give a little more detail on what you are trying to achieve here at all? I can see how to do what you need, but it doesn't seem like a very efficient solution. Also, what is the range of potential numbers you will be testing for? Is there an upper limit, lower limit, only a set pool of values (such as 100, 200, 300 etc.)

OK. Here is the method for 0, 1 and 2s

Create a counter for 0, 1, 2s etc.

-> Store the number in a string object, using the "Number to string" expression in the string object expression menu
* Always
- Set NumberVersionOfText$ to str$(Number)

-> Do a fast loop (in the system object)
* Always
+ Set "number of 0s" to 0
+ Set "number of 1s" to 0
+ Set "number of 2s" to 0
+ Start loop "Count" Len(String$("NumberInText)) (in the system object expression menu)

* On loop "count"
* Mid$(NumberVersionOfText, LoopIndex("Count"), 1) = "0"
- Add 1 to "Number of 0s"

* On loop "count"
* Mid$(NumberVersionOfText, LoopIndex("Count"), 1) = "1"
- Add 1 to "Number of 1s"

* On loop "count"
* Mid$(NumberVersionOfText, LoopIndex("Count"), 1) = "2"
- Add 1 to "Number of 2s"

This should work.

For an arbitrary number of possibilities, I'd create a map (Named Variable Object or anything else that supports key-value pairs) and loop over the list once by using Get Alterable Value with Index N (I can't remember the exact expression):

- Get the alterable value
- Increment the value's key in the map by 1

The map will hold the number of occurrences of each number. In the given example:

Alterable value 0 = 0
Alterable value 1 = 1
Alterable value 2 = 1000
Alterable value 3 = 500
Alterable value 4 = 1000

Loop: Gets 0. Map now contains:
0=1

Loop: Gets 1. Map now contains:
0=1
1=1

Loop: Gets 1000. Map now contains:
0=1
1=1
1000=1

Loop: Gets 500. Map now contains:
0=1
1=1
1000=1
500=1

Loop: Gets 1000. Map now contains:
0=1
1=1
1000=2
500=1

Now loop over each key in the map, and you have the number of occurrences of that number.