I am still working on "mental math" with her. I want her to be able to do some basic addition and subtraction in her head without using her fingers. I am focused on working to the 10s with her (pairs that create 10). For example, 6 and 4, 7 and 3, 5 and 5, 8 and 2, 9 and 1. She started to show memory of her 'pairs.' I was able to do some subtraction using the concept of the 'pairs that create 10' and then go into addition and subtraction to the 100 (eg. 100-60 = 40, 6 and 4 are paired to create 10).