Trade-First Subtraction 1.0 Released

Independent developer Esa Helttula has released a new educational math app Trade-First Subtraction 1.0 for iPhone and iPod touch. It is the first Everyday Math app in the iTunes App Store. The app can be used to teach and study the trade-first subtraction method.


Everyday Mathematics

Everyday Mathematics is a new mathematics curriculum developed by the University of Chicago School Mathematics Project. In the United States over 3 million students in 185,000 classrooms are currently using Everyday Mathematics. Parents may find it hard to help their children with the "new math" and apps like the Trade-First Subtraction can help both children and parents.



The Trade-First Subtraction Method Step by Step

The trade-first subtraction method is the focus algorithm for subtraction in the Everyday Mathematics curriculum. The method breaks down a subtraction problem into a series of easy steps. The Trade-First Subtraction app allows the user to solve subtraction problems step by step and animates all the steps. All of the "trading" or "borrowing" is done first. Then the subtractions are solved for each column. This gives the method it's name, "trade-first."


The Interface Supports Learning

If the user presses the wrong button the answer will appear above the keyboard but it will not move. "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", said assistant professor of mathematics education Tim Pelton in his review of Column Subtraction, a sister app of Long Division that uses the same kind of input method. The app is easy to use and it has an intuitive interface with customizable colors and other settings.


The app has the following settings:
* Each number can have from 2 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
* The lines separating the columns can be hidden

Pricing and Availability:
Trade-First Subtraction 1.0 is only $0.99 (USD) and available worldwide exclusively through the App Store in the Education category. This is a new app in my series of popular educational math apps for iPhone. My other mathematics apps are Long Division, Long Multiplication, Column Addition and Column Subtraction.


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