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Question Whenever Jasoda has to subtract 9 from a number, she subtracts 10 and adds 1 to it.
For example, 36 – 9 = 26 + 1.
(a) Do you think she always gets the correct answer? Why?
(b) Can you think of other similar strategies? Give some examples.
(a) Yes, she will always get the correct answer if she subtracts 10 from a number and then adds 1 to the result instead of directly subtracting 9 from the number, because subtracting 10 and adding 1, i.e., -10 + 1 = -9, is equivalent to subtracting 9 from the number. As 36 – 9 = 27 or (36 – 10) + 1 = 26 + 1 = 27 (b) Do it yourself.