What is the best way to whiten my teeth on a budget?

I can't afford to buy those Whitestrips or anything...is there a toothpaste that works almost as well?
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While Crest White Strips are the best, they are quite pricey. I usually brush my teeth with baking soda after brushing with tooth paste. Basic Arm and Hammer works just fine. It takes a little longer than the pricey stuff, but ti does work.
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