Place Value Lab

About this tool

The Place Value Lab is a base-10 blocks workmat with a twist no physical set can offer: three displays stay linked while you work. Tap blocks onto the mat and the numeral builds itself in labeled place columns — and beneath it, the number word assembles too, with its tens part and ones part glowing in the same colors as the columns. Twenty-four shows twenty in teal and four in coral; the connection between what we SAY and what we WRITE stops being invisible.

The bundling moment is the heart of place value, so the Lab makes it a moment worth watching. Collect ten loose ones and the mat offers a bundle — one tap, and the cubes squeeze together with a rubber-band snap and become a ten rod that slides into the tens column. It works the other way too: break a ten back into ten ones with a pop. That unbundling IS borrowing, and the premium Subtract lab stages it: take 17 from 42, hit the wall at two loose ones, and the borrow becomes something children physically do rather than a rule they memorize.

A Show me mode turns it into a gentle challenge — build the number you see, or the trickier version: build the number you HEAR. When a child hears the word and builds the digits reversed, the tool never buzzes; it names what they actually built, lights up the word parts, and invites another look. Premium adds the hundreds place and lets you save your class's own numbers — days of school, kids in the room — the numbers children actually care about. Free in the browser, no account needed.

How to use it in class

• Project the mat and tap the + buttons to add blocks — the numeral and the number word build along with you.
• Collect ten ones and tap the glowing bundle button: the snap into a ten rod is the place-value lesson in one second.
• Tap any digit to interrogate it — its part of the word and its blocks flash together, and it is spoken alone.
• Switch to Show me for build-what-you-hear challenges; misses get a warm comparison, never a buzzer.
• In the Subtract lab (premium), watch borrowing become physical: break a ten, remove the marked blocks, done.

Classroom ideas

• The daily number ritual: build the day-of-school count every morning and save it — the hundred-day party builds itself.
• Zahlendreher clinic: say a tricky number aloud, let children build it, then tap the digits to see which part of the word said what.
• Estimation warm-up: show a pile of ones, ask "can we make a ten?", and let a child perform the bundle for the class.
• Partner check: one child types a number on the keypad, the other reads the word aloud before the speech button confirms it.
• Borrowing theater: run one subtraction on the projector before workbook time — the pop of the breaking ten is the anchor image for the whole lesson.