I have an application where a younger audience can improve their math skills. It is still in development phase and I have made some usability tests observing users getting their hands on the application for the first time. I have to tell them how to interact with the application at a certain step, before they get going in learning math. I need to improve the interaction design and explain to the users how to do - and I need to know which option that could do the trick.
From my point of view I have three main options:
- Introduce a wizard which explains to the user how the application works. This wizard can later be found in the about screen (which is not built yet)
- Let the user view a video, which lets the user see how the learning game is played
- Use an explanatory callout after a certain amount of time. This callout can be turned off in the settings screen (which is not built yet)
How the application works
The user opens the application and sees an expression to solve. If the user clicks the textbox (image 1), the soft keyboard opens and the user can enter their answer. If the length of the answer is equal the correct answer (calculated in the background) - the answer is checked. If the answer is correct a green circle visualize below the expression, the textbox is disabled and a green border is visible on the expression (image 2). If the answer is wrong, the circle is red and the textbox is still enabled letting the user have another try at the expression. So far every user follows the flow.

The problem
When the textbox is disabled, the user is supposed to click the expression text (having a green border on image 2) to get a new expression and enable the textbox for answer again. Users tend to get stuck here, and I really need to in some way tell the user to click the label. Are my options above good enough, or is their another way to let the user know what to do?

