Column Subtraction

Column Subtraction helps students learn and practice the column subtraction method step by step.

The app aligns the numbers automatically so students can focus on solving each column. Renaming is animated visually, helping students understand how values are moved between columns. Renaming can be done automatically or manually, and renaming over several columns is supported.

Students can solve randomly generated problems or enter their own subtraction problems. The number of digits can be adjusted, making the app useful for different skill levels.

Column subtraction is also known as columnar subtraction, long subtraction, or longhand subtraction. Renaming is also known as regrouping, trading, or borrowing.

Features:

• Subtract 2 or 3 numbers
• Each number can have 1–5 digits
• Randomly generated or manually entered problems
• Automatic number alignment
• Manual or automatic renaming/regrouping
• Supports renaming over several columns
• Current operation for each column can be hidden
• Operands of the current operation can be highlighted
• Adjustable animation speed
• Different interfaces for iPhone and iPad
• 25 six-piece animal jigsaw puzzles
• Puzzle feature can be turned on or off

Reviews and Endorsements:

Professor Tim Pelton, assistant professor of Mathematics Education at the University of Victoria: “If your goal is to help your child to master the traditional subtraction algorithm then Column Subtraction may be the ideal App.”

“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.”

Teacher endorsement:

“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.” — Rita Zeni, Ecole Sandy Hill Elementary, Abbotsford, BC, Canada

Other iDevBooks Math Apps:

Other iDevBooks math apps include Column Addition, Long Division, Long Multiplication, Lattice Multiplication, Visual Multiplication Table, Fraction Math, Partial Differences Subtraction, Partial Quotients Division, Partial Sums Addition, and more.

Feedback:

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

Privacy:

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