Brain Out Level 166

Overview

Level 166 asks you to "Try to make the biggest possible number by moving only 2 matchsticks." The board displays the digit 308 built out of brown matchsticks with red rounded heads, sitting above a yellow input bar and a numeric keypad with digits 0 through 9 plus Clear and OK buttons. Most players treat this as a normal matchstick puzzle and start morphing 3 into 9 or 0 into 8, but the Brain Out twist is that you are allowed to break the 0 apart entirely and turn its spare sticks into brand-new digits off to the side. The largest number you can legally form with only two moves is 31181, entered on the keypad rather than by physically rebuilding the matchsticks.

• Difficulty: Hard
• Estimated moves: 4

Step-by-Step Solution

1. Look at the starting number 308 and ignore the urge to turn 3 into 9 or 0 into 8. Those are small three-digit changes and the puzzle is asking for something bigger.
2. Identify the middle 0 as the digit you will disassemble. A 0 made of matchsticks has top, bottom, left, and right sticks. You are allowed to move exactly two of them.
3. Move the top horizontal stick and the bottom horizontal stick off the 0. With its top and bottom gone, the two remaining vertical sticks of the 0 stand side by side, which reads as the two-digit block 11. The original 0 has effectively become 11 inside the number.
4. Use the two sticks you pulled off to add a new trailing digit 1 to the right of the 8. This turns the original 308 into the five-digit number 31181: the leading 3 is untouched, the broken-apart middle 0 now reads as 11, the original 8 stays in place, and a new 1 sits at the far right.
5. Tap the yellow input bar above the keypad to bring up the numeric pad. Type the digits 3, 1, 1, 8, 1 in order. The input bar should now read 31181.
6. Tap the blue OK button on the keypad. The level-complete pop-up appears with the line "Cool!" Tap Next to continue. If the game rejects the entry, double-check that you typed five digits starting with 3 and ending with 1, not a three-digit number like 999.

Strategy & Reasoning

The puzzle punishes normal matchstick instincts. Improving each digit one at a time only gives you small gains: 3 to 9 is one stick, 0 to 8 is one stick, but you have only two moves total, so the ceiling stays around 998 or 999. The Brain Out trick is to stop thinking in three digits and start thinking about how to add digits. Matchstick puzzles in this game routinely let you split a digit into multiple digits on the same layout.

The middle 0 is uniquely useful because it is the only digit whose sticks can be re-read as something else. Once the top and bottom horizontals are gone, the two verticals look like the digit 1 twice, which immediately expands the number from three digits to four. The two sticks you removed become a fifth digit 1 off to the right. A five-digit number starting with 3 is already 30,000 and up, which dwarfs any three-digit result you could squeeze out of 308.

People try 999 first because it is the obvious largest three-digit number from 308 with two moves. That is a legitimate construction, but it is not the largest number the layout allows. The game accepts 31181 because it respects the "moving two sticks" rule while exploiting how a broken 0 is interpreted. The congratulatory line "Cool!" is the game acknowledging that you found the digit-splitting trick rather than doing the digit-maximizing trick.

Tips & Common Mistakes

• Stopping at 999. It is a valid three-digit upgrade, but the puzzle expects the larger five-digit construction 31181.
• Moving sticks out of the 3 or the 8. Those digits are fine as they are; the lever is the middle 0, which can be split into 11.
• Forgetting to type the result on the keypad after rearranging. The matchstick drawing is the setup; the actual answer is entered with the numeric buttons.