|Other Retailer||Price Checked Time||Their Price in AUD||Our Price|
|Amazon US||15 days ago||51.83||$31.97||You save $19.86|
|Amazon UK||4 days ago||50.58||$31.97||You save $18.61|
|Book Depository US||2 days ago||35.24||$31.97||You save $3.27|
Allen Downey is a Professor of Computer Science at the Olin College of Engineering. He has taught computer science at Wellesley College, Colby College and U.C. Berkeley. He has a Ph.D. in Computer Science from U.C. Berkeley and Master's and Bachelor's degrees from MIT.