Changes

<math>a_{1}+a_{2}+a_{3}+\dots+a_{N}=\sum^{N}_{n=1}a_{n}</math>

<math>a_{1}+a_{2}+a_{3}+\dots+a_{N}=\sum^{N}_{n=1}a_{n}</math>

This is usal pronounced "the sum of 1 to N of a n" (note that this is still an ambigous statement which is why mathematics is more riquerous written down).

This is usally pronounced "the sum of 1 to N of a n" (note that this is still an ambigous statement which is why mathematics is more riquerous written down).

If we are conserned with particular number we can move the starting index. For example,

If we are conserned with particular number we can move the starting index. For example,