How do I get Microsoft Word, Power Point, and ActivInspire on my iPad?

I am applying for a Donor's Choose grant, and have to include all costs. I am trying to get an iPad to use for my classroom, especially for Flipboard use. I would like to be able to use it with my Promethean Board as well. How do I get Microsoft Word, Power Point, and ActivInspire (for the Promethean Board) loaded onto an iPad? Do they cost anything?

iPad

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