To solve a math problem, just point the phone camera toward the math problem and you will automatically get the result in a second or two. Make sure that the image is clear and bright enough.
Holding firmly and writing with a neat handwritting will make scanning faster.
If the result is not shown after two to three seconds, then either the math problem is not supported or the app is unable to properly recognize the text (for example, due to poor light conditions or camera not being clean).
You can also use the math keyboard, which acts as an advanced calculator.