The problem appears with a text field below it$.$ This text field should already

have focus:

Math Facts Practice

Addition

$5+3$

Score: $4_{?}$

Time Left: ${13}_{?}$ seconds

The user can enter values using the keyboard or the buttons on the screen.

When an answer is correct:

The score should be incremented by $1.$

The next problem should appear.

The answer field should be emptied and focus should be put back on

the answer field, so the user can start typing the next answer.

The time$-$left countdown should start at $30$ and decrease by $1$ every

second.