A number series is a list that follows a rule. You choose the number that comes next, or the number that fills a gap in the middle. Some items are a simple count. Others change by a growing amount or by two steps at once, depending on the grade. QuizPrint also draws on number-matrix items in this same quantitative set, where the rule sits in a small grid rather than a single row. Grades 1 through 8 each have a worksheet. The sample is Grade 5. QuizPrint is not affiliated with Riverside Insights, and these worksheets are not official CogAT questions.