Base 10 versus Base 8 math

Embrie figures out the information stored in Declan’s head is coded in base-eight, not base-ten math. But why? Base-ten math is the math we use every day. We count by tens, it feels very natural. Truth is, it’s not some universal rule, it’s probably because (most of us) have ten fingers.

Also, not all cultures count using base-ten math. Yuki, a now-extinct Native American dialect, used octal counting because people counted using the spaces between their fingers rather than the fingers themselves. The Pamean languages of Mexico also use an octal system, because their speakers count on the knuckles of a closed fist. In 1716, King Charles XII of Sweden asked a famous Swedish polymath to develop a number system based on 64 instead of 10, instead he proposed 8 as the base.

Octal math is also used in computing, base-8 representation simplifies binary code expression and is essential for modern computers. If computers use base-8 math, it makes a lot of sense the Girl in the Glass would share information with ALVA using a counting system the machines would understand.