Eli5: Why is 2^9 + 2^9 = 2^10

Question

Middle school teacher here, and this is driving me crazy! Thanks!

In: 2

Answer 1

This is because another way to write this is just 2 * 2^9. Just like 4 + 4 is 2*4. 2^9 is just 2 times itself 9 times. That means 2^10 is 2 times itself 10 times or 2 * 2^9 or 2^9 + 2^9.