I need a Powerpoint for a class of low-level, low-literacy Grade 8 students for their math class. I am reviewing mental math strategies that have so far been taught (that adding and subtracting 2 is the same as finding the last or next even/odd number), then teaching them to break higher addition problems down. For instance, they can learn that to add or subtract 3, they just subtract or add 2, then 1, and it will come to the same result. And adding/subtracting 4 is the same as subtracting two twice, or counting backwards/forwards to the next two/preceding two even/odd numbers.