Tally O'Malley (MathStart by Stuart J. Murphy - TALLYING - Tally marks are a useful tool for children to keep track as they count, and for data collection. Grouping tally marks also reinforces counting by fives.
Finding JOY in Grade: Algebra Pieces, Differentiation, and Fixing a Mistake. Son was placed in ALL pre-AP classes. This will come in handy. Just because I'm a math nerd, doesn't mean I can explain it well :)