Powers of Two Reference

Memorizing powers of 2 will speed up your binary conversions and help you recognize patterns in code. Here are the first 16:

$2^0 = 1$, $2^1 = 2$, $2^2 = 4$, $2^3 = 8$, $2^4 = 16$, $2^5 = 32$, $2^6 = 64$, $2^7 = 128$, $2^8 = 256$, $2^9 = 512$, $2^{10} = 1024$, $2^{11} = 2048$, $2^{12} = 4096$, $2^{13} = 8192$, $2^{14} = 16384$, $2^{15} = 32768$.

Notice $2^{10} \approx 1000$ (actually 1024). So $2^{20} \approx 1$ million, $2^{30} \approx 1$ billion. These approximations help you estimate algorithm runtimes and memory usage.