When building troops there is a default #1 in the amount to build block. that #1 cannot be deleted or removed by the backspace until another number is in that block. For example; with the 1 in the block, and I desire to make 500 units, I must type the 5, which will show "15" in the block. then I have to go and delete the "1" and then type the "00" to make the 500.