Splitting an equation into multiple lines [duplicate]

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I want to display the following equation: The LaTeX code I have made is as follows:

$PaD^{i}=\left [ \frac{(1-\frac{n_{1}}{N})\times M(i,1)}{m}+\frac{\sum_{t=2}^{m}[(1-\frac{n_{t}}{N}\times \frac{n_{t-1}}{N})\times M(i,t)\times M(i,t-1) )]}{m}+\\ \frac{\sum_{t=2}^{m}[(1-\frac{n_{t}}{N}\times \frac{N-n_{t-1}}{N})\times M(i,t)\times (1-M(i,t-1))]}{m}\right ]\times 100\%$

Is there any way to break the right side of the equation into three lines so that it can fit the page?

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Here are two possible solutions. The first is kind of minimal, in that it uses an align* environment and provides for two line breaks. (Well, I also replace most instances of \times with \cdot, and I eliminated a spurious ) in the middle row.)

The second solution goes further towards making it easy on your reader to actually read and comprehend the material. E.g., by writing \frac{1}{m} at the beginning of each of the three additive terms, the remaining material can be typeset using larger lettering. After all, the material that's being summed up is at least as important as the \frac{1}{m} term, right? The second solution also gets rid of all \cdot directives and places the 100\% block at the start, to give it more visual prominence. \documentclass{article}
\usepackage{amsmath} % for 'align*' env.

\begin{document}
\begin{align*}
&=\biggl[ \frac{(1-\frac{n_{1}}{N})\cdot M(i,1)}{m}\\
&\qquad+\frac{\sum_{t=2}^{m}[(1-\frac{n_{t}}{N}\cdot \frac{n_{t-1}}{N})\cdot M(i,t)\cdot M(i,t-1) ]}{m}\\
&\qquad+\frac{\sum_{t=2}^{m}[(1-\frac{n_{t}}{N}\cdot \frac{N-n_{t-1}}{N})\cdot M(i,t)\cdot (1-M(i,t-1))]}{m}
\biggr] \times 100\,\%
\end{align*}

\begin{align*}