Base Ten Blocks ES

This is such a great app to demonstrate regrouping. This app engages my students with special needs. They love using this app. I can watch their light bulbs going on when they use it to regroup tens and ones. However, I am having glitches when subtracting. Frequently, the program develops a glitch when regrouping tens back to ones. It will be working fine, and then it just stops allowing you to move a ten to the ones side. I hope this will be repaired soon.