# Column Subtraction 1.4 - Practice Math Problems and Solve Jigsaw Puzzles

in Education (E)

[prMac.com] Espoo, Finland - Independent developer Esa Helttula has released Column Subtraction 1.4. It is an update of the educational math app for iPhone and iPod touch. Parents and educators have found the app very useful because it allows children to master the column subtraction method in an intuitive and fun way.

Reviewed by Tim Pelton, assistant professor of Mathematics Education

Tim Pelton, assistant professor of Mathematics Education at the University of Victoria reviewed Column Subtraction 1.0: "If your child is familiar with the traditional algorithm they will likely be able to improve their mastery of the procedure using this application. With the 'show current operation' option turned on, they are constantly reminded of the next step, which can lead to efficient practice of the procedure. Then by turning off the current operation your child is able to practice remembering the steps on his/her own. Because no wrong entries are allowed the app provides a passive form of positive reinforcement and your child will likely improve in both confidence and competence with respect to the procedure. "

Easy to Use

The numbers are aligned automatically so that you can concentrate on solving the operations for each column. Pressing the borrow-button carries out borrowing which is animated step by step so you can see what happens. Borrowing over several columns is also supported.

After you solve the operation for each column the correct answer will fly to the right place. If the user presses the wrong button the answer will appear above the keyboard but it will not move.

Use random problems or input your own numbers

You can let the app pick the problems for you. Column Subtraction 1.4 has a new feature that allows you to input your own numbers. Customers had requested this feature.

25 Six-piece Jigsaw Puzzles

The puzzles are pictures of cute animals. Every time the user solves one subtraction problem, he will see one more piece of a six-piece picture puzzle.

To see all 25 complete puzzles the user has to solve about 200 column subtraction problems (Some pictures may appear twice before all different pictures have been shown). The picture puzzle feature can be turned off and on at any time.

Column Subtraction 1.4 has the following new features:
* 25 6-piece jigsaw puzzles of animals
* The jigsaw puzzles can be hidden
* Problems can be random or custom
* Support for Retina display in iPhone 4 and new iPod touch
* Support for fast app switching in iOS4

Other Features of the Column Subtraction App:
* The number of numbers to subtract can be 2 or 3
* Each number can have from 1 to 5 digits
* The current operation for each column 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

Device Requirements:
* iPhone, iPod touch, and iPad
* Requires iOS 3.0 or later
* Supports iOS 4.0
* 3.8 MB

Pricing and Availability:
Column Subtraction 1.4 is only \$3.99 (USD) and available worldwide exclusively through the App Store in the Education category. Column Subtraction is part of a popular series of 16 educational math apps for iPhone. Other mathematics apps in the series include Fraction Math, Long Division, Lattice Multiplication, Long Multiplication and Column Addition.

Esa Helttula is an independent developer located in Espoo, Finland. He specializes in apps for the iOS that help teach math skills. He is formerly an algorithm visualization researcher at the university of Tampere in Finland. Column Subtraction is one of his sixteen iPhone math apps. Copyright (C) 2010 Esa Helttula. All Rights Reserved. Apple, the Apple logo, iPhone and iPod are registered trademarks of Apple Inc. in the U.S. and/or other countries.

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