What it teaches
Turning a sentence into a sum. That step is the one children find hardest and the one most practice skips, so the numbers here are deliberately easy: a child should fail this game because they picked the wrong operation, never because the arithmetic beat them.
Word problems are also the place where reading and maths meet, and where a child who is good at both can still be stuck because nobody has shown them how to join them.
How it works
The problem appears in writing and is read aloud, so a child who is still slow at reading is not blocked from the maths. Then a number pad.
On a wrong answer the help pulls out the two numbers and asks what is happening to them — are they being put together, or is one being taken from the other? Only after that does it show the sum.
What to look for
Ask the child to say the story back in their own words before they touch the keypad. Most wrong answers here are a misread, not a miscalculation, and retelling catches it immediately.
Two-step problems arrive at the higher levels. They are a genuine step up, and worth waiting for.