Riddle: How can you make the written number "one" disappear using just a single extra letter?

Introduction / Context:
This is a playful word riddle about spelling rather than arithmetic. The question asks how to make "the number one" disappear, but the trick is that it really talks about the written word "one". You are supposed to change the letters in a simple, clever way so that the new word means that the original has vanished. Riddles like this test your ability to connect meaning, spelling and small changes in words.

Given Data / Assumptions:

• The focus is on the number "one" as written in English letters: O N E.
• We are allowed to modify this word using a small, simple change.
• The question suggests that the number should "disappear", so the new word should express the idea of something being gone.
• Options include adding or removing letters, turning the paper and underlining the word.

Concept / Approach:
A clever solution is to add the letter G at the beginning of "one". This changes the word from "one" to "gone". The word "gone" literally means that something has disappeared or is no longer present. So by adding a single letter, you transform the name of the number into a word that describes its disappearance. This matches the riddle perfectly and uses minimal change, which is characteristic of classic word puzzles.

Step-by-Step Solution:
Step 1: Write down the word "one". Step 2: Ask yourself what simple word changes could convey the idea of disappearing. Step 3: Notice that adding the letter G in front gives "gone". Step 4: Understand that "gone" means something is no longer here; it has disappeared. Step 5: Recognise that this fits the riddle exactly: you have made "one" disappear by turning it into "gone". Step 6: Check that no other suggested modification produces such a clean and meaningful transformation.

Verification / Alternative check:
Verify the logic by reading the transformation aloud. You start with "one", a number. After adding G, the word becomes "gone". If someone says, "The number one is gone," they mean it has disappeared. Therefore, the modified word both visually and semantically represents the disappearance. Options that simply erase letters or flip the page do not produce a meaningful new word expressing disappearance.

Why Other Options Are Wrong:
Option B, erasing the letter O to get "ne", produces a meaningless fragment rather than a real English word.

Option C, turning the paper upside down, may make the word harder to read but does not transform it into a new word about disappearance.

Option D, replacing E with A to form "ona", again does not create a meaningful English word that fits the riddle.

Option E, underlining the word, simply changes its appearance, not its meaning.

Common Pitfalls:
Some learners overthink and try to manipulate the number as a mathematical symbol instead of treating "one" as a word. Others attempt complicated letter changes that do not result in real, meaningful words. Many language based riddles rely on adding or removing just one letter to produce a clever new word, so it is useful to practice spotting those simple shifts.

Final Answer:
You can make "one" disappear by adding G in front so that it becomes "gone".