1.9 Skip Counting in NinesSkip counting lays out the patterns fundamental to arithmetic. In these self-directed workbooks students will internalize these patterns and pave the way to mastery over numbers. Skip counting in nines is really just counting backwards. The only tricky part is remembering not to change the tens' when the number ends in zero: 0, 9, 1 8, 2 7, 3 6, etc. PrerequisitesStudents should be familiar with skip counting in tens a