When teaching any of the four operations (addition, subtraction, multiplication and division) the problem solving aspect is usually tricky for students. Getting a sense of meaning is the key to understanding word problems. Younger students can do a sketch of the situation in the word problem to help them to visualize what is happening. Older students can skip that part and go straight to the steps below. This is a poster that I use to guide my students along as they do problem solving. I like to see written statements that are clear and the poster below shows the specific sequence that I prefer.
Here is an example of a subtraction word problem that is solved using the steps shown above.
I still have a few kids who forget to 'attach the noun' as seen above, the noun 'students' was attached to the answer. Many times they would just write 'Answer = 50' and I'll ask 'Fifty what?... Fifty cars?... Fifty trees?' Then they'll make their corrections by adding the word that applies to the answer.
If you are teaching problem solving with your students, you may need these free addition and subtraction word posters which show the many different operation word clues for addition and subtraction.