Addition Calculator Sum of numbers. a b a + b 155 Step-by-step with your numbers: 1. Values used: 2. a = 100 3. b = 55 4. a + b = a + b = 100 + 55 = 155 Did we solve your problem today? 👍 Yes 👎 No Thanks for the feedback! Simple addition. FAQ More numbers? Add one pair at a time. Related calculators Subtraction Calculator Difference between two numbers. Multiplication Calculator Product of two numbers. Division Calculator Quotient of two numbers.