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. All three places are free — hundreds, tens and ones — along with the whole mat, the number word and the printable sheets. Premium adds the Subtract lab, the full library of numbers behind Show me, and saving 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), the child decides: some problems need a ten broken open and some do not, and the mat is what tells them which.

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.