Samastipur, Bihar. The math teacher was about to introduce two new concepts. “You can change the orders, but it won’t alter the sum or the result,” contended the tutor, explaining the commutative property of addition in algebra. If you add four to two, he shared an example with a bunch of attentive students in a state-run municipal school, you will have the same result as when you reverse the order. Similarly, a change in the order of a group of numbers doesn’t change the sum. “This is an associative property of addition,” he underscored. A few students looked perplexed.
(This story appears in the 15 December, 2023 issue of Forbes India. To visit our Archives, click here.)