Expert: Paul Klarreich - 10/12/2006

Question
My daughter brought home a series of questions and we figured them all out except this one.

1 2 3 4 = 7

The numbers have to stay in order of 1234 and when added,subtracted,multiplied or divided they have to equal 7.  My wife and I are drawing a blank too and her teacher insists that there is a solution.

Answer
My daughter brought home a series of questions and we figured them all out except this one.

1 2 3 4 = 7

The numbers have to stay in order of 1234 and when added,subtracted,multiplied or divided they have to equal 7.  My wife and I are drawing a blank too and her teacher insists that there is a solution.
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Hi, Jeff, and family,

I don't see the obvious solution, either, so I am passing this on to MY daughters, who are much better in math than I am.

So far, all I can come up with is:

1 + (3 * 4) / 2

which violates the 'order' condition, and

1^2 * 3 + 4

[1^2 means  one-to-the-second, or one-squared.]
which requires exponentiation, not listed among your allowed operations.

If I come up with anything better, I'll let you know.

Paul
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Daughter #2 says:  

I bet the teacher intended 1 + (3*4)/2. You could depict that without changing the order of the numbers if you use the long division sign rather than the division symbol.

I think she means to write it as:
[VIEW WITH A FIXED FONT, SUCH AS COURIER.]
      _________
1 +  2 ) [3 * 4]