App Shopper: Left-to-Right Subtraction (Education)

App Activity

Aug 22 '12	$2.99 -> $3.99
Aug 08 '12	$3.99 -> $2.99
Mar 05 '12	Version 2.0
Feb 28 '12	$1.99 -> $3.99
Aug 12 '11	$3.99 -> $1.99
Oct 18 '10	$.99 -> $3.99
Oct 16 '10	$3.99 -> $.99
Sep 01 '10	$1.99 -> $3.99
May 23 '10	$.99 -> $1.99
Feb 09 '10	New App: $.99, v1.0

About AppShopper

For more information on Contacting Us, App Submissions, and Advertising, visit our About page

Left-to-Right Subtraction

iOS Universal

This math app can be used to teach and study the left-to-right subtraction method. The app is easy to use and it has an intuitive interactive interface with customizable colors and other settings. The user can solve random subtraction problems and each step is made clearer with an animation.

The Left-to-right Subtraction Method

The left-to-right subtraction method is a two-step process. In the example 936 - 581, the number to be subtracted is first written in an expanded form: 500+80+1. Each of the parts is then subtracted from the starting number. In our example 936-500=436, 436-80=356 and finally 356-1=355.

In the Everyday Mathematics curriculum the left-to-right subtraction method is one of the algorithms for subtraction.

Endorsed by teachers

Rita Zeni, Ecole Sandy Hill Elementary, Abbotsford, BC, Canada:

"The math apps by Esa Helttula allow students to practice and reinforce the specific computation strategies taught in class, with as much or as little scaffolding as necessary.
They also provide individualized feedback to each student, with an immediacy that is not always possible through pencil and paper practice. Being able to adjust the level of difficulty to suit their needs is also very motivating for the students. I am so glad to have come across this great educational tool!"

The App is Easy to Use

Each step of the multi-step process is animated and the numbers are aligned automatically so that the user can concentrate on solving the operations for each step.

After you solve each sub-operation the correct answer will fly to the right place. If you press the wrong button the answer will appear above the keyboard but it will not move.

Difficulty can be set with Settings:

-The numbers can have 2 or 3 digits.
-The current operation can be hidden.
-The operands of the current operation can be highlighted.
-Colors of the interface can be changed.
-The speed of the animations can be set.

Part of a series of iDevBooks math apps

This app is one of the 17 successful and acclaimed iDevBooks math apps for iPhone, iPod Touch, and iPad. Wired.com, iear.org, and other sites have endorsed the apps and they are used in dozens of schools. For more information please visit http://idevbooks.com

The iDevBooks math apps contain no ads, in-app purchases, push notifications, tracking, or any kind of data collection whatsoever. The settings screen of each app contains a link to idevbooks.com website for support and feedback. For more information please see the privacy policy at idevbooks.com.

Feedback & requests for new features

All feedback is welcome and new features will be added based on user feedback.

What's new

- The app is now universal and it has custom interfaces for iPhone and iPad
- The user can input his or her own problems
- On the iPad the app can be used in portrait or landscape orientation
- New icon
- Minor bug fixes

Please give feedback and get information about 16 other math apps by visiting http://idevbooks.com