Microsoft Office: what are the best cheap alternatives?

I’m only a casual Word and Excel user and I don’t want a hefty monthly chargeEvery week a Guardian Money reader submits a question, and it’s up to you to help him or her out – a selection of the best answers will appear in next Saturday’s paper.Ever since the Microsoft Office (Word and Excel) licence expired on my home computer, I get annoying pop-ups asking me to subscribe at £7.99 a month. I’m only a casual user. What are the best cheap alternatives? I