Using numbers in sentences can be tricky sometimes. There are a number of grammar rules that concern numbers, but two of them come to mind. They are, never start a sentence with a number unless it is spelled out; and if a number is less than ten, it should be spelled out, unless it is date or time. Stay tuned for a post looking into the usage of date, time and numerical listing. For now, it may help to keep these two rules in mind.
Sara bought eight apples. But when I counted them, there were 12 apples in the bag.
Thirty-two percent of the runners were late to the start line.
Say What You Mean. Mean What You Say, and number it correctly.