Marble Jar Studio

Marble Drop

Listen to the clinks. Keep the total in your head.

Jar A

Drop here

?

Jar B

Choose a marble

Tap to choose a colour, or drag one marble to the jar opening.

Marbles per drop

Jar size

Choose 1–10, then drop a group.

How many could there be?

Your estimate

Ready? You will see a jar for three seconds.

Marbles in each jar

Which jar has more?

By how many?

Compare the jars. Choose one, then enter the difference.

Marble Jar Studio

Choose an activity

How to use

Marble DropChoose a colour and a group size from 1 to 10. Each press drops that many marbles. You can also drag a coloured marble to the jar opening to add one marble at a time. Listen for the first clear clink as each marble lands. Keep the total hidden while children count, then use Show total to check. Empty jar cancels any unfinished drop.

Flash & GuessChoose a number range and press Show for 3 seconds. The jar is then covered. Enter an estimate using the keypad and check it. A guess within two marbles earns a “Very close!” message. Look again shows the same jar for another three seconds. New jar gives a fresh challenge.

Compare JarsChoose Jar A, Jar B or Same, then enter the difference. If the jars are equal, the difference is zero. Choose the correct jar and a difference within two to earn a “Very close!” message. Keep trying for an exact answer. Reveal totals is available for teacher-led discussion.

Keyboard & soundUse number keys, Backspace, Delete to clear, and Enter to check an answer. In Marble Drop, Space drops a group when the page background is focused. Sound starts after a tap. Use the speaker button to mute it.

Display

Fullscreen hides browser controls. On iPad, Safari keeps its own swipe-to-exit gesture.

Screen fit uses the available browser area without entering native fullscreen. Browser controls may stay visible.