NumIO learning activity

Fill the missing number in the equation

Fill the Gap turns an unknown number into a small puzzle that learners can solve with relationships they already know.

Learning goal

Use the known numbers and the operation to work out the missing value.

How to play

Read the equation, identify what is missing, and tap the number that makes the complete sentence true.

Classroom idea

Have learners explain how they checked the equation after finding the gap rather than relying on a guess.

Frequently asked questions

What does “Fill the Gap” practise?

In “Fill the Gap”, learners use the known numbers and the operation to work out the missing value.

What is the difference between practice and speed run in “Fill the Gap”?

Practice gives five untimed questions. Speed run adds a timer that gets shorter with each correct answer, ends when wrong answers or timeouts use up three lives, and lets you post your score to this activity’s ranking with a nickname.

Is “Fill the Gap” free, and do I need an account?

Yes, it is free and there is no account or sign-up. Practice completions and speed run bests are saved in this browser; a nickname is only needed if you choose to post a speed run score to the ranking.

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