This is how I visualize numbers. 5 and 10 are the primary blocks. 7 is a 5 with a 2 on top that could either slide off or take 3 from another number. Great to s

This is how I visualize numbers. 5 and 10 are the primary blocks. 7 is a 5 with a 2 on top that could either slide off or take 3 from another number. Great to see it being taught.