Hence the use "prove" rather than prove. But the length of the real proof is beside the point. We teach them about 1 and 2 before going to 1+1=2. And when we d

Hence the use "prove" rather than prove. But the length of the real proof is beside the point. We teach them about 1 and 2 before going to 1+1=2. And when we do go to 1+1=2, we show it to them using objects and counting. We don't simply tell "here's the function for addition, just put numbers into to to solve problems".