Unit Conveyor
See 1 kg become 1000 g
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
1 kg is 1000 g. Watch the number change as the unit changes, on a factory line. Wrong answers get an explanation, not just "try again". Ads only on the report screen.
1 kg is 1000 g. 1 m is 100 cm.
Unit Conveyor shows what happens to a number when the unit changes — so children see it,
instead of memorising it.
■ The unit staircase
Length, weight, volume and time units are laid out as steps.
Send a crate up a step and the number gets smaller; send it down and it gets bigger.
The crate travels between steps so the cause is visible.
■ The conversion line
Four boxes come down the conveyor. Pick the one with the right answer.
The wrong boxes are not random numbers.
"Counted one zero too few", "multiplied instead of divided", "split an hour into 10" —
each one is built from a mistake children actually make.
So no box can be dismissed at a glance. Every question needs real thinking.
■ Shipping slips (word problems)
"We used 2 m and 50 cm of ribbon. How many cm altogether?"
Matching two different units before adding them is a separate skill, and it gets its own line.
■ Report
Shows the percentage correct for each unit, so you can see which unit needs practice.
■ Safe to hand to a child
・Free. No in-app purchases and no subscriptions
・Ads appear only on the report screen, never while a question is on screen
・No full-screen ads and no video ads
・Results are stored on the device only, and are deleted with the app
・No camera, microphone, location, contacts or notifications
Designed so a primary-school child can use it alone.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Yoshihide Maehama, 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 Linked to You
The following data may be collected but it is not linked to your identity:
- Location
- Identifiers
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Yoshihide Maehama
- Size
- 33.3 MB
- Category
- Education
- Compatibility
Requires iOS 16.4 or later.
- iPhone
Requires iOS 16.4 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Japanese
- Age Rating
4+
- 4+
- Copyright
- © 2026 Yoshihide Maehama