Numbers & Place Value
Understand our number system
$0.99 · Designed for iPad
Also Included In
Explore large and small numbers and discover how place value works – interactively. This is not a drill app but an open environment for exploring and experimenting.
Understanding place value is one of the most important foundations in mathematics: it underpins mental and written calculation strategies, decimals and much more.
HOW IT WORKS
Drag the digits up and down with your finger. Go beyond 9 and watch ten items bundle into one item of the next place. Go below 0 and see how the next place is "unbundled".
Swipe or tap the quantity below a digit to change it.
At the bottom of the screen, choose how the quantity is shown: place value counters, base-ten (Dienes) blocks, euro money, dot fields, 3D base-ten material and more.
TOOLS ON THE RIGHT
- Speaker: listen to the number being read aloud.
- Speech bubble with check mark: read the number aloud yourself and check whether you read it correctly.
- Expand: shows, for example, 142 as 100 + 40 + 2.
- Dice: roll a random new number.
- Speech bubble with dots: say a number and watch it appear.
- Question mark: some places are covered, the number is read aloud and you fill in the missing digits.
MORE OPTIONS
- Use the grey arrows to add or remove places – explore numbers up to 100 trillion.
- Move the decimal point to work with decimals down to millionths.
- Tap a place label (O, T, H …) to change its color.
- Swipe across a digit to cover it; tap the cover to enter your answer and get feedback.
- Number words above the digits in matching place colors – optionally as "Say Ten" number words (e.g. 284 = "two hundred eight ten four").
- Many settings in the app: thousands separator, place labels, speech rate, show or hide tools and representations, protect settings.
- Share a setup or task with your class via QR code.
- English (UK/US) and German.
- Also available in the browser: zahlen.urff.app
IDEAS FOR THE CLASSROOM
- Number dictation: show 3,469.
- Keep adding one to the ones. What happens when you go past 9?
- Show 340. What happens when you take one away from the ones? What about 300?
- Show 5,216 and expand it: which numbers make it up (5,000 + 200 + 10 + 6)? What about 5,316?
- Listen to a number, then change one place. Can you read the new number correctly?
- Tap the question mark and solve some tasks – the app counts them for you.
- Why does the leading zero in 0453 disappear? Why does the zero stay in 204 or 240?
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Bugfixes
The developer, Christian Urff, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Christian Urff
- Size
- 8.2 MB
- Category
- Education
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - iPad
Requires iPadOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later.
- iPhone
- Languages
- English and German
- Age Rating
4+
- 4+
- Made for Ages 6–8
- Copyright
- © 2026 Christian Urff
