Hi, I'm in a year 2 class and we have been adding 10's. We have done it with the hundred square and related it to place value. The majority of the class have grasped it now but it took a lot of work to get there. iM due to go onto subtracting 10 now but I'm worried that this may confuse them! Should I go onto this or leave it and come back to it in a couple of weeks? Thank you!