Decimal System Review

Decimal (base-10) uses ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. This is what you learned as a child and use every day.

The number 3,742 means $3 \times 10^3 + 7 \times 10^2 + 4 \times 10^1 + 2 \times 10^0$, which equals $3000 + 700 + 40 + 2 = 3742$. Each position is a power of 10, starting from $10^0 = 1$ on the right.

Why base-10? Humans have ten fingers. Other bases follow the same logic but use different numbers as the foundation. Now let me show you base-2, where everything changes.