A short Python 3 program that I used with year 6 at St Martin's School in Jersey

spellings.py

import random

def removeRandomLetterFrom(word):
    lengthOfWord = len(word)
    randomNumber = random.randint(0, lengthOfWord-1)
    letterToRemove = word[randomNumber]
    newWord = ""
    for letter in word:
        if letter == letterToRemove:
            newWord += "_"
        else:
            newWord += letter
    return newWord

words = [
            "second",
            "following",
            "together",
            "without",
            "outside",
            "suddenly",
            "different",
            "coming",
            "between",
            "across"
        ]

correctSpellings = 0
for word in words:
    print("How do you spell", removeRandomLetterFrom(word), "?")
    spellingTry = input()
    if spellingTry == word:
        print(" - Well done, that's correct!")
        correctSpellings += 1
    else:
        print(" - Sorry, that's not correct.")

print("You got", correctSpellings, "out of", len(words), "correct")