import re

def extract_operation(question):
    ops = {
        "add": "add", "plus": "add", "+": "add",
        "subtract": "subtract", "minus": "subtract", "-": "subtract",
        "multiply": "multiply", "times": "multiply", "*": "multiply",
        "divide": "divide", "over": "divide", "/": "divide"
    }
    for word in question.lower().split():
        if word in ops:
            return ops[word]
    return None

def extract_numbers(question):
    return [float(n) for n in re.findall(r"[-+]?\d*\.\d+|\d+", question)]