We have been using base 10 blocks and cubes to show numbers but have also been using virtual base 10 blocks (Number Pieces Basic which is a free app) and also drawing representations of the blocks with a drawing app (MaxDoodle) on the iPad. You can see representations of both in our pictures.
Today kiddos had to represent numbers and also prove how they knew one was larger than the other. They could choose how they wanted to show it. It was great to see them take ownership not only of their learning but of how they felt most comfortable showing what they knew. As we finished, kiddos had the opportunity to come up and explain their thinking. I am excited by the growth I am seeing not only with everyone's ability to show what they know and explain their thinking but also with their use of technology and choosing the right tool/app to do the job.