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Left-to-Right Subtraction


Left-to-Right Subtraction
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  • App Store Info

Description

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.

Other iDevBooks math apps

iDevBooks math apps have been reviewed and endorsed by Wired.com, IEAR.org, Edudemic.com, Teachers with Apps, and other respected sites and organizations.

Some of the other 24 iDevBooks math apps are Column Addition, Long Multiplication, Long Division, Column Subtraction, Visual Multiplication Table, Partial Differences Subtraction, Partial Products Multiplication, Partial Sums Addition, Decimal Rounding, etc.

Feedback and requests for new features

New ideas to make this app better are welcome. Please visit idevbooks.com to give feedback.

Privacy

This app has no ads or in-app purchases and it does not transmit any data during the operation of the app. This app also does not contain any links to other apps or the web.

What's New in Version 2.3

Interface updates for iOS 7.

Please visit http://idevbooks.com if you have questions or feedback about any of the 26 iDevBooks math apps.

Screenshots

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