How to make 100 out of 123456789

You can create 100 from the digits 123456789 using various arithmetic operations and arrangements. One popular solution is: 123 + 45 - 67 + 8 - 9 = 100, which uses addition and subtraction while maintaining the digit sequence. Other valid solutions include 123 - 45 - 67 + 89 = 100, or using multiplication and division such as (1 + 2 - 3 + 4 + 5 + 6) × (7 + 8 + 9) ÷ 4, though this requires creative interpretation of "using" the digits. This type of puzzle develops numerical reasoning skills and demonstrates how mathematical operators can transform a fixed set of digits into specific targets. In educational settings, these challenges help students understand order of operations (PEMDAS/BODMAS) and encourage flexible thinking about number relationships. The constraint of maintaining digit order adds complexity—if you're allowed to rearrange digits, the possibilities expand dramatically, such as 15 + 36 + 47 + 2 = 100. These mental math exercises appear frequently in recreational mathematics and cognitive assessments because they test both computational skills and creative problem-solving abilities.