Tricky Test 2 Level 30

Overview

This level shows the number "508" built from matchsticks and asks "If you can only move 1 match, what's the biggest possible number?" There is a keypad (0–9, delete, enter) for typing your answer. The solution is to move one matchstick to transform 508 into 909: take the lower-left match from the 8 (turning it into a 9) and place it on the upper-right of the 5 (turning it into a 9).

• Difficulty: Hard
• Estimated moves: 1 match move + typing

Step-by-Step Solution

1. Read the question: "If you can only move 1 match, what's the biggest possible number?"
2. Look at the number 508 built from matchsticks.
3. Move the lower-left matchstick away from the 8. Removing that segment turns the 8 into a 9.
4. Take that removed matchstick and place it on the upper-right side of the 5. Adding that segment turns the 5 into a 9.
5. The resulting number is 909.
6. Type "909" on the on-screen keypad and press enter to submit.

Strategy & Reasoning

The puzzle challenges you to find the largest three-digit number achievable by relocating exactly one matchstick. The digit 8 has a removable lower-left segment; taking it away leaves a 9. That freed match can be added to the 5's missing upper-right segment, converting it into another 9. The middle digit 0 stays unchanged. This yields 909, which is larger than alternatives like 588 or 908. The video shows the answer being entered as 909, confirming this as the intended solution. The constraint of moving exactly one match is the key boundary; you cannot add or remove matches, only relocate one.

Tips & Common Mistakes

• Mistake: trying to change more than one matchstick. Correct: move exactly one match from the 8 to the 5.
• Mistake: producing a smaller number like 588. Correct: the target is 909 by turning both the 5 and the 8 into 9s.
• Mistake: misplacing the moved matchstick. Correct: remove the lower-left segment of the 8 (making it 9) and add it to the upper-right of the 5 (making it 9).
• Mistake: forgetting to type the answer on the keypad. Correct: after visualizing 909, enter it using the on-screen number pad.

The reason 909 is the largest is that moving the lower-left segment off the 8 turns it into a 9, and adding that same segment to the 5's missing upper-right converts it into another 9. The middle 0 stays unchanged. Alternatives like 588 or 908 are smaller because they leave one of the leading or trailing digits at a lower value. The constraint that only one match may move means you cannot add or remove segments, only relocate the single freed piece.

The key takeaway is that only one match may move, so you must choose the relocation that maximizes the number. Removing the lower-left of the 8 makes it 9, and adding that segment to the 5's upper-right makes it 9, giving 909. The middle 0 stays unchanged, and you type the result on the keypad.