A few things come to mind. Easy remedies on installing strings and concerns of breakage: First, agreeing with the above comment to 'grease' the nut groove near the scroll with a pencil (lubricating it). Also, make sure that the groove is wide enough (often not) and that it will not pinch the string just as one that is not properly lubricated.
when using a digital tuner, it will not tell you WHERE you are in relation to the correct octave. In other words, you might quickly go past the note you need to tune to, then going up to the next higher octave will break that string as well. Use your ears to make sure you are not going DOUBLY high. http://www.violin-strings.com

A few things come to mind. Easy remedies on installing strings and concerns of breakage: First, agreeing with the above comment to 'grease' the nut groove near the scroll with a pencil (lubricating it). Also, make sure that the groove is wide enough (often not) and that it will not pinch the string just as one that is not properly lubricated.

When using a digital tuner, it will not tell you WHERE you are in relation to the correct octave. In other words, you might quickly go past the note you need to tune to, then going up to the next higher octave will break that string as well. Use your ears to make sure you are not going DOUBLY high.