Solution a27192a 2 - What Number.

Problem: A quarter of twice a number is three less than the number. What is the number?

Solution 2:
This second solution method is by equation solving.

We translate the problem text to an equation and solve the equation:

The only possible answer is therefore that the number is 6.

Comment 2:
The equation solving method has the advantage of directly computing the correct answer, and also to guarantee that this is the only answer.

In middle school, the trial and error method is typically used in the lower grades while equation solving is part of the curriculum for the upper grades.

Problem solving activities often lead successful students to the discovery of equation solving techniques, before these are formally taught.