Related Clues:

• Put 2 and 2 together
• Lengthen (with "to")
• Ancient pyramid builders
• Word found on a dipstick
• Also say
• Cookbook verb
• Toss in
• Toss into the mix
• Ring true
• Verb used in recipes
• Gibe, with 'up'
• Keep talking
• Count up
• Factor a sum
• Compute, so to speak