Related Clues:

• Does sum work
• Does basic math
• Increases (with "to")
• Puts on the pile
• Contributes to the mix
• Introduces, as an ingredient
• Does a certain math problem
• Opposite of subtracts
• Finds a total
• Chimes in
• Includes, as a tip
• Calculates a total
• Performs basic arithmetic
• Tots up
• Gets to the bottom line