# 20/20 Primes and Factor Trees — The tutor in your pocket. > Educational app for prime factorization, LCM, and GCD with step-by-step guidance. (iPhone/iPad app by Walter Kissach.) - Source: https://appshunter.io/ios/app/2020-primes-and-factor-trees/id300173695 (this page in markdown: same URL + `.md`) - Developer: [Walter Kissach](https://appshunter.io/developer/293232788) - Category: Education, Reference - Price: $0.99 - Rating: 5.00/5 from 1 App Store ratings · 12 written reviews indexed - Age rating: 4+ - Requires: iOS 18.0 · 3 MB - Languages: English - Released: 2008-12-18 - Data updated: 2026-06-10 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/2020-primes-and-factor-trees/id300173695/reviews.md ## What is 20/20 Primes and Factor Trees? A power learning aid combines Coaching Calculators and Guides to help students master prime factorization, LCM and GCD. Prime factorization : - Prime factorization by factor trees LCM or Least Common Multiple : - LCM by prime factorization - LCM by listing multiples GCD or Greatest Common Divisor : - GCD by prime factorization - GCD by listing divisors You develop understanding quickly as you work with the calculator and see each step of the process in detail. ## Key features - Prime factorization by factor trees - LCM by prime factorization - LCM by listing multiples - GCD by prime factorization - GCD by listing divisors - Coaching calculators - Detailed step-by-step process ## Recent user reviews (10 of 12) All indexed reviews: https://appshunter.io/ios/app/2020-primes-and-factor-trees/id300173695/reviews.md ### 5/5 — Helped with pre- algebra *2015-02-26* This was a great help today with pre-algebra work. I'm going to look into getting the whole MathFlair app. Great resource for jr and sr high math classes. ### 5/5 — Full answers without needing to be loaded! *2013-08-25* Get this app IF YOUR IN 8th grade! Please!!! ### 1/5 — What... *2013-01-08, version 3.1* This app is for little kids and is completely unhelpful. Stupid. ### 5/5 — Amazing *2013-01-03* It has everything I'm doing in school right now and is simple to use. 👍👍👍👍👍 ### 5/5 — Love this App, but why IOS6? *2012-10-13* I am a high school math teacher, and our school is an "ischool", where the students each get to check out an iPod for educational purposes. I absolutely love this app to help my students learn to simplify square roots. But I've recently discovered that some of them cannot update to IOS6 because some of the devices are a bit too old. I am glad it is updated for the new IOS, but SO bummed that it doesn't work for earlier IOS versions. Can that be fixed? ### 1/5 — Unable to know anything about it, it doesn *2012-04-18, version 2.2* It doesn't appear in my list of ipad, but in my ipod, iphone apps. ### 5/5 — Great app *2012-03-25* Help me get me grade up ! In it help me study too 5 out 5 ! ### 5/5 — great app *2012-02-06* it was exactly wat i needed! ### 5/5 — Great app *2011-05-03* easy to use ### 5/5 — :] *2010-10-19* Got my grade up in algebra ## Frequently asked questions about 20/20 Primes and Factor Trees ### What math concepts does 20/20 Primes and Factor Trees teach? 20/20 Primes and Factor Trees teaches prime factorization, Least Common Multiple (LCM), and Greatest Common Divisor (GCD). It covers methods like factor trees and listing multiples/divisors. ### How does 20/20 Primes and Factor Trees help students learn? The app acts as a tutor by providing coaching calculators and detailed step-by-step guidance. This allows students to develop understanding quickly by seeing each process in detail. ### What is the price of 20/20 Primes and Factor Trees? 20/20 Primes and Factor Trees is a paid app, priced at $0.99. This one-time purchase grants access to all its features. ### On which devices can I use 20/20 Primes and Factor Trees? 20/20 Primes and Factor Trees is available for iPhone and iPad. It is designed to work on Apple's mobile operating systems. ### How often is 20/20 Primes and Factor Trees updated? The latest version of 20/20 Primes and Factor Trees is 9.1, last updated on September 4, 2025. This indicates active development and support for the application. ### What is the age rating for 20/20 Primes and Factor Trees? 20/20 Primes and Factor Trees has an age rating of 4+. This suggests it is suitable for young learners and covers fundamental mathematical concepts. ### Does 20/20 Primes and Factor Trees have ads? No, 20/20 Primes and Factor Trees does not contain advertisements. As a paid application, it offers an uninterrupted learning experience. ### What do users like about 20/20 Primes and Factor Trees? Based on its rating of 5.0 stars from 1 rating, users likely appreciate its effectiveness as a learning aid. The detailed step-by-step guidance and focus on core number theory concepts are probable strengths. ## Version history (last 5 releases) ### 9.1 — 2025-09-04 This version is compatibile with iOS 18. ### 9.0 — 2024-04-09 This version contains minor bug fixes. ### 8.9 — 2024-03-29 iOS 17 compatibility and minor bug fixes. ### 8.8 — 2024-03-26 iOS 17 compatibility and minor bug fixes. ### 8.7 — 2022-12-11 This version has minor bug fixes. ## Apps similar to 20/20 Primes and Factor Trees | App | Rating | Price | Category | | --- | --- | --- | --- | | [Napier's Bones Simulation](https://appshunter.io/ios/app/napiers-bones-simulation/id1093899282) | — | $1.99 | Education | | [Factors and Multiples](https://appshunter.io/ios/app/factors-and-multiples/id909532243) | — | $2.99 | Education | | [FormulaBar](https://appshunter.io/ios/app/formulabar/id396415852) | — | $0.99 | Education | | [Mnemo Route](https://appshunter.io/ios/app/mnemo-route/id955836076) | 3.7 (3) | $4.99 | Education | | [Ladhe's Primes](https://appshunter.io/ios/app/ladhes-primes/id1532128975) | 5.0 (1) | Free | Education | | [Korean Words 4 Beginners](https://appshunter.io/ios/app/korean-words-4-beginners/id459331279) | — | $2.99 | Education | ## More apps by Walter Kissach - [Quadratic Inequalities](https://appshunter.io/ios/app/quadratic-inequalities/id293232785) - [Circles and Equations](https://appshunter.io/ios/app/circles-and-equations/id293619582) - [Even and Odd Polynomials](https://appshunter.io/ios/app/even-and-odd-polynomials/id293668394) - [Quadratic Factoring](https://appshunter.io/ios/app/quadratic-factoring/id294040055) - [Quadratic Equations](https://appshunter.io/ios/app/quadratic-equations/id294195555) - [20/20 Fraction Basics](https://appshunter.io/ios/app/2020-fraction-basics/id298766849) All apps by Walter Kissach: https://appshunter.io/developer/293232788 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*