Bug: Bare number accepted as valid equation — no operator required

[Bindkushal]

What's the bug?

Two rules are not being enforced when input is typed via keyboard:

1. Broken buttons (shown in red) can be bypassed by typing on the keyboard.
2. Just typing the target number directly (e.g. 116) is accepted as a valid equation — no operators needed.

Steps to verify the bug

1. Run the activity
2. Note the broken buttons (e.g. 0, 3, 9 shown in red)
3. Note the target number (e.g. 116)
4. Type 116 directly using your keyboard (don't click any buttons)
5. Press Enter
   That was my target, your target will be different

Result: 116 = 116 accepted, +17 pts awarded
Expected: Should be rejected — broken digit used + no operator present

Why this happens

Broken button validation only blocks on-screen button clicks. The equation validator doesn't check whether the typed string contains broken digits.

Suggested Fix

The validator should also check:

• Does the equation contain actual target digits? → reject
• Does the equation have at least one operator? → reject if not

Screenshot

[Bishoywadea]

closed via #13