What if you only had ones and zeros to work with? Let’s start counting up from zero. 0,1,… but how do we represent the number 2 without using another digit other than 1 or 0? Think about how we represent the number 10. Instead of having a unique symbol for every number, we represent 10 with a one and a zero. The one represents that there is one multiple of 10^1 (ten to the first power), and the zero represents that there are zero multiples of 10^0 (Remember that anything raised to the power of zero is equal to one). Adding these two together gives you 10+0=10.

Back to binary: how can we represent the number 2 with only ones and zeros? Each place in the number will now represent a multiple of 2 instead of a multiple of 10.

If you look at the diagram, you can see that two can be represented by 10. There is 1 multiple of 2^1, and zero multiples of 2^0. Adding these two together, 2+0 = 0.

Following this idea, in the number 01001000, there is a 1 in the 26 place and a 1 in the 23 place. 2 * 2 * 2 * 2 * 2 * 2 = 64, and 2 * 2 * 2 = 8. If you add 64 and 8, you get 72. If you feel like you need extra practice with this, try this __code.or__g binary game out!