Final answer:
The correct number of pumps for a Small 151 Crazy Shake cannot be determined without specific context or a standard reference. This information might be proprietary to a business's recipe for their shakes.
Step-by-step explanation:
The number of pumps used for a Small 151 Crazy Shake is not provided within the context of this question. This might be proprietary information specific to a business and its drink recipes. Without the exact context or a standard reference for this beverage, it would not be possible to accurately answer whether it is 2 pumps, 3 pumps, 4 pumps, or 5 pumps. Typically, the number of syrup pumps can vary depending on the establishment's recipe for their shakes. In a learning environment, it's important to base answers on provided materials or common knowledge.