Math fluency (MF) is the ability to quickly and accurately solve simple math exercises. Proficiency in MF is one of the buildings of arithmetic achievement during school. However, so far only paper and pencil tests have been used to assess MF. In the current study, we present the BGU-MF (Ben-Gurion University Math Fluency) test, a new computerized tool for MF. MF was assessed by accuracy rates, response times, and the number of performed exercises. In order to examine its reliability, participants performed the test twice. In order to examine its validity, participants performed manual format of MF from the Woodcock-Johnson battery. Results indicated high reliability and validity of the BGU-MF test. Performance in the BGU-MF also predicted abilities in the math matriculation exam and psychometric exam. The advantages of the BGU-MF computerized tool over the manual tool and further implications of the BGU-MF are discussed.