In support of the inhibition theory of negative transfer, Campbell and Robert (2012) found that numerical addition practice led to negative transfer on numerical multiplication. The present work sought to test the inhibition theory of negative transfer by assessing alphabet addition verification practice (i.e. B+3=E, true or false?) to transfer in alphabet multiplication verification (i.e. Cx4+M, true or false?). Four experiments varied the number of days of practice with each day including 4 blocks of 120 addition problems. On the final day, participants were presented alphabet multiplication problems some of which included the same values as the practiced addition problems (e.g. B+3=E and Bx3+E). Results from experiments 1 – 3 suggest participants demonstrated significant learning of alphabet addition, with increased learning with more practice. Yet no negative transfer to alphabet multiplication occurred. Results from the forth experiment in this series will be presented.