Brain Out Level 143

Overview

A matchstick equation reads 18 = 1, and the prompt asks to make it true by moving the matches. The digits are built from matchsticks with red round heads, so individual sticks can be slid between positions. The intended rearrangement turns the left side into a subtraction that balances against the right side: 1 minus 0 equals 1.
The matchstick digits and signs are built from individual sticks with red heads, so each piece can slide to a new position rather than being fixed printed symbols.

• Difficulty: Regular
• Estimated moves: 2

Step-by-Step Solution

1. Study the matchstick construction of the 1, the 8, the equals sign, and the final 1. Each digit is made of movable sticks rather than fixed printing.
2. Slide the match forming the leftmost 1 further to the left, giving it space to act as the first digit of the new expression.
3. Move the horizontal match from the middle of the 8 so the 8 collapses into a 0, and place that freed stick between the 1 and the 0 as a minus sign.
4. Read the rebuilt equation: 1 - 0 = 1, which balances because 1 minus 0 is indeed 1.
5. Leave the equation in this state. The level accepts the true matchstick arrangement once the minus sign and the 0 are in place.

Move the leftmost 1 aside to leave room for the rebuilt expression, then take the middle horizontal stick from the 8 and watch that digit collapse into a 0. Place the freed stick between the remaining 1 and the 0 as the minus sign, and read the rebuilt equation to confirm it balances. Leave the arrangement as 1 - 0 = 1 and let the level accept it. If the digits do not read cleanly, check that the 0 still has its outer frame and that the minus stick sits between the two numbers.

Strategy & Reasoning

Matchstick puzzles reward seeing which single stick changes both a digit and a sign at once. The original 18=1 cannot be balanced by changing the right side, so the left side must be rebuilt. Removing the middle stick of the 8 turns it into a 0, and that same stick becomes the minus sign, producing 1-0=1 with no extra material added. The equation stays true under ordinary arithmetic once the sticks are repositioned. Matchstick puzzles rely on one stick changing both a digit and a sign at once; here the middle stick of the 8 doubles as the minus sign. The original 18=1 cannot balance by changing the right side, so rebuilding the left into a true subtraction is the only path, and no extra material is added to the board.

Tips & Common Mistakes

• Treat each match as movable; the digits are not printed on the board.
• The freed middle stick of the 8 doubles as the minus sign, so one move changes both number and operation.
• Check that the rebuilt equation reads 1 - 0 = 1 before leaving the arrangement.