Unit 12 · Base Systems
Base Systems
Mathematics · Grade 7
What You Will Be Able To Do
🔟Explain what base ten actually means, in terms of place value
➗Convert any number into base two or base five by repeated division
↩️Convert back using place values, which also checks your first answer
💻Say why every computer in the world stores numbers in base two
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We write numbers in groups of ten, and it feels like the only possible way, but it is a habit that comes from having ten fingers. Nothing in mathematics requires it.
Presenter notes: Open with a question nobody has been asked before. Write 347 on the board and ask why we group numbers in tens. Most students have never considered that there might be a reason, and the honest answer is slightly deflating: because we have ten fingers. Nothing in mathematics requires it. Hold up both hands and say that if humans had eight fingers, every number in the room would be written differently and none of them would have changed value.