Brahmagupta · Mathematics

Fortunes and Debts: Making Negatives Legitimate

Brahmagupta’s first systematic rules for signed arithmetic - positive quantities as ‘fortunes’ and negatives as ‘debts’ - which made numbers less than nothing into legitimate quantities, with correct sign rules, roughly a thousand years before Europe would accept them.

What you'll be able to recall

You learned that Brahmagupta treated negative numbers as ‘debts’ and positives as ‘fortunes,’ gave the full and correct rules of signs for adding, subtracting, multiplying and dividing them, and thereby made negatives legitimate quantities long before the West accepted them. Explain the sign ru…

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