Column Subtraction vs Math Geometry

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.

“Math Geometry: Learning 2D and 3D Shapes” is designed for school teachers and children aged 5-10 years to study 2D and 3D shapes, and the attributes of shapes. The app contains the hi-quality figures and provides a fun and interactive way to learn the shapes, so your kids will love this app. The app provides following functionality / topics / concepts: • Learning and testing 2D Shapes and their attributes – sides and corners • Learning and testing 3D Shapes and their attributes – vertices, faces and edges • Ability to rotate any 3D shape in any direction – it is a fun and effective way to memorize each shape • Different question types: identifying a shape by a given picture, by a given name and by its attributes • Manage the test content – you can exclude/include a specific shape from the test content • Choose the number of questions – from 10 to 40 • Progress report – ability to see the latest and best student results by test type (2D / 3D) and by question type (shape names / attributes of shape) • Ability to see the correct answer, and learn the related shapes when the student makes a mistake. This option is configurable, so it can be switched off if required • Ability to reset the statistics • Sound control Enjoy!