Math skills and prerequisites
What this game practices
- Compare decimals to one decimal place
- Identify values inside an open interval
- Count forward in tenths
Explore: Decimals & timing · Number patterns
Before playing
- Read decimals such as 1.2 and 2.8
- Recognize less-than signs
- Understand the order of numbers on a number line
Getting started
Choose PLAY and read the two endpoints around the moving counter.
The counter rises in steps of 0.1.
Choose STOP! with a mouse or touch, or press Space, to freeze the displayed number.
How to play
- Read the target as lower endpoint < moving number < upper endpoint.
- Choose a value inside the gap and watch the counter approach it.
- Stop after the lower endpoint and before the upper endpoint. Stopping exactly on either endpoint is incorrect.
- Read the feedback: a correct stop earns one point; SO CLOSE!, TOO EARLY! and TOO LATE! do not.
- Each resolved attempt advances automatically. Complete all 20 to see your correct-answer total and best streak.
- Choose PLAY AGAIN for a new session or BACK TO MENU from the results.
TRY THE REASONING
Worked example
1.2 < counter < 2.8
- The displayed target is 1.2 < counter < 2.8.
- Choose 2.0 as a safe value inside the interval and stop when the counter displays it.
- 1.2 and 2.8 are boundary values. Stopping exactly on either gives SO CLOSE! but no point.
Strict less-than signs exclude the endpoints. The valid tenths here run from 1.3 through 2.7.
Scoring, success and round endings
- Each correct answer adds 1 to SCORE, for a maximum of 20.
- STREAK counts consecutive correct stops. An incorrect stop resets it; BEST records the longest streak in the session.
- The finished 20-attempt session is the platform reward accomplishment, based on its correct answers.
Modes, settings and progression
Rounds 1–7
The gap is 1.2 to 1.6 units wide.
Rounds 8–14
The gap narrows to 0.8 to 1.2 units.
Rounds 15–20
The gap narrows again to 0.5 to 0.9 units. Counter speed stays the same.
Strategies and troubleshooting
- Aim near the middle of the interval to leave room for your reaction time.
- Say a few tenths aloud before stopping: 1.7, 1.8, 1.9, 2.0.
- Use the feedback to distinguish being on a boundary from being outside the whole interval.
Classroom and home use
Suggested activity: Before each stop, ask a partner to name three valid tenths in the interval. Afterward, explain why the stopped value is inside, on a boundary or outside.
Questions to discuss
- Does the lower endpoint count? Which symbol tells you?
- What is a useful middle value for this gap?
- How many tenths lie strictly between 1.2 and 2.8?
This is a teaching suggestion, not an extra mode or a promised learning outcome.
Play and progress
Guest play does not require an account. For shared arcade coin rewards, use a verified account with an active player profile. Game scores and shared coins are different; only confirmed platform awards update the shared balance. Follow each game’s guide for its own restart and resume behavior.
Play Egg Timer
