Generate Random Math in Python 3

This program will ask the user a series of questions about two numbers. These two numbers will be generated randomly between 1 and 10 and it will ask the user 10 times. At the end of these 10 questions the program will display how many the user got correct out of those questions. Each question should randomly decide between asking for the product, sum, or difference. Separate the question asking into a function, as well as the validating user input.

I tried using with three product, sum or difference in random to generate. I tried to use z = random.randint(1, 4) is to select from 1 is product, 2 is sum, or 3 is difference and then I used with if variable z is 1, then do product math or if var z is 3, then it should be difference like this x / y, but I couldn't figure it finish it up. I have the expected result when I first run with product but it works so I just need to add with sum and difference included.

EXPECTED OUTPUT with product (Some are incorrect for testing with scores):

> python3 rand3.py
What is 3 x 4
Enter a number: 12
What is 3 x 7
Enter a number: 27
What is 6 x 3
Enter a number: 18
What is 7 x 10
Enter a number: 70
What is 9 x 10
Enter a number: 90
What is 9 x 7
Enter a number: 72
What is 5 x 9
Enter a number: 54
What is 6 x 8
Enter a number:
Incorrect Input!
Enter a number: 48
What is 1 x 5
Enter a number: 5
What is 10 x 3
Enter a number: 30
You got 7 correct out of 10

My Work for Product Only (Success):

import random

def askNum():
  while(1):
    try:
      userInput = int(input("Enter a number: "))
      break
    except ValueError:
      print("Incorrect Input!")

  return userInput

def askQuestion():

  x = random.randint(1, 100)
  y = random.randint(1, 100)

  print("What is " + str(x) + " x " +str(y))

  u = askNum()

  if (u == x * y):
    return 1
  else:
    return 0

amount = 10
correct = 0
for i in range(amount):
  correct += askQuestion()

print("You got %d correct out of %d" % (correct, amount))

My Currently Work: (I am working to add sum and difference like the expected output

UPDATED: After the expected output works well with product so I am trying to add new random int for z with 1-3 which means I am using with 1 is for product, 2 is for sum and 3 is difference by using if-statement by given random select. I am struggle at this is where I stopped and figure it out how to do math random because I am new to Python over a month now.

import random

def askNum():
  while(1):
    try:
      userInput = int(input("Enter a number: "))
      break
    except ValueError:
      print("Incorrect Input!")

  return userInput

def askQuestion():

  x = random.randint(1, 10)
  y = random.randint(1, 10)
  z = random.randint(1, 4)

  print("What is " + str(x) + "  "+ str(z)+ " " +str(y))

  u = askNum()

    if (z == 1):
      x * y  #product
      return 1
    else if (z == 2):
      x + y #sum
      return 1
    else if (z == 3):
      x / y #difference
      return 1
    else
      return 0

amount = 10
correct = 0
for i in range(amount):
  correct += askQuestion()

print("You got %d correct out of %d" % (correct, amount))

OUTPUT:

md35@isu:/u1/work/python/mathquiz> python3 mathquiz.py
  File "mathquiz.py", line 27
    if (z == 1):
    ^
IndentationError: unexpected indent
md35@isu:/u1/work/python/mathquiz>

With this currently output, I double checked with corrected Python formatting and everything are sensitive, and still the same as running output. Any help would be more appreciated with explanation. (I hope my English is okay to understand since i'm deaf) I have started this since on Saturday, than expected on time to meet.