Related Clues:

• Opposite of subtract
• Put numbers together
• Do this to find a sum
• Do a math function
• Find a math sum
• Do some simple math
• Perform a math operation
• 2 + 2, e.g
• Make a sum
• Put a couple of things together
• Create sums
• Simple arithmetic function
• Come up with sum-thing?
• Do "sum" easy math
• Find the 64 Across