How to debug the multiplication questions

Question

Eg. There are three times as many adults as children.

There are two times as many birds as zebras

How do debug these questions in the form of an equation?

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shoumkrish · Answer

“There are three times as many adults as children” means the number of adults is thrice the number of children.

In equation form, A = 3C, if A and C denote adults and children respectively.

Similarly, B = 2Z for birds and zebras.

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achandak · Answer

Thanks.. I usually end up writing inverted proportion

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Hadesara · Answer

Shouldnt it be the other way around?

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ccooley · Answer

I love that you've asked this question. This is one of the most common simple math errors to make, and the fact that you've recognized the error means you're already ahead of most people who make it.

The trick to 'debugging' these is to test out some simple numbers to make sure your equation makes sense. For example, if there are two times as many birds as zebras, it would make sense to have 20 birds, and 10 zebras, just based on the language. 20 is two times as many as 10. So if you wrote down the equation '2b = z', try plugging in those numbers to make sure that your equation makes sense. 2b = z 2(20) = 10 Hmmm... that's not correct. So, your equation must be wrong. But if you wrote down 'b = 2z', try plugging in the numbers now: b = 2z 20 = 2(10) 20 = 20 That's a correct statement, so the equation 'b = 2z' was the right one. If you develop a habit of doing this, you can do it very quickly in your head every time you write an equation like this one. I tend to make this mistake myself, so I always just quickly plug in some simple numbers in my head that fit the problem, to double check that I translated correctly.

TheGraceful · Answer

I echo the same. Glad some else also thinks the same way. Anyways, the question was interesting.

How to debug the multiplication questions

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