Comparison

Decimal Rounding vs Mnemo Major System Trainer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Decimal Rounding

This educational app helps users learn and practice rounding decimal numbers. It offers guided step-by-step problem-solving with customizable settings for a stress-free learning experience. Ideal for students and anyone needing to master decimal rounding.

Highlights
  • Learn decimal rounding
  • Customizable problems
  • Random problem generation
  • Step-by-step guidance
  • Stress-free learning environment
  • Adjustable interface colors and animations
Features
Currently charting
Read full description

Decimal Rounding helps students learn and practice rounding decimal numbers step by step. Students can solve randomly generated problems or enter their own decimal numbers. Decimals can be rounded to the nearest whole number, tenth, hundredth, or thousandth. They can also be rounded to 0, 1, 2, or 3 decimal places. The app guides students through each problem one step at a time. There are no penalties for wrong answers, no timers, and no pressure. The clean interface helps create a calm learning environment. Features: - Decimal numbers can have 2–8 digits - Randomly generated or manually entered problems - Round to the nearest whole number, tenth, hundredth, or thousandth - Round to 0, 1, 2, or 3 decimal places - Customizable interface colors - Adjustable animation speed - Different interfaces for iPhone and iPad - Portrait and landscape orientation on iPad Other iDevBooks Math Apps: Other iDevBooks math apps include Column Subtraction, 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.

About

Mnemo Major System Trainer

Learn and master the Major System, a powerful mnemonic technique for remembering numbers. This app offers an integrated training program with visual aids and statistics to help you create and optimize your personalized number-to-image encoding system.

Highlights
  • Personalized Major System creation
  • Integrated training program
  • Reaction time analysis
  • Number sequence to image generator
  • Pre-installed Major System (0-99)
  • Customizable terms and images
  • CSV Import/Export
Features
Read full description

The Major System is an effective method for encoding numbers into images. Using this mnemonic technique, remembering a sequence of numbers is highly improved compared to simple memorization. (Synonyms: Major System, Master System, Digit Code according to Aimée Paris, Phonetic System, conversione fonetica etc.).  The Mnemo Major System Trainer allows you to create a personalised Major System for the mnemonics Major System. With the help of the integrated training programme - the trainer - the Major System can be quickly learned and further optimised. For this purpose, a traffic light system of reaction times to queried terms is used, which effectively exposes sub-optimally selected images and allows rapid optimisation in the development of one's own Major System. A summary overview of the reaction times - here called statistics - additionally supports this process. In addition to the master system, trainer and statistics, the generator was added as a further component, which enables the translation of arbitrarily long numerical sequences into the images of the major system. To further facilitate the process of creating your own major system, a ready-made major system for the number range 00 - 99 has been integrated. In addition, a list of alternative terms that satisfy the rules of the major system was added to each term. Attention: The selected images are to be understood as examples and logically cannot be the optimal memory image for everyone. (In ancient times, for example, teachers of mnemonics refrained from giving their students ready-made mnemonic systems. The students were supposed to develop their own systems. Even then, it was known that one's own associations facilitate memorisation). Features: INTUITIVELY DESIGNED LEARNING PROGRAM • Multiple training possibilities • Question mode for images or numbers • Training with major system terms instead of pictures • Free selection of the number range to be learned with optional restrictions to specific reaction time ranges, questions answered incorrectly or not yet processed terms • Training level indicator PREINSTALLED MAJOR SYSTEM • Major System Terms and selected images for the numbers 0 – 99 and 00 – 09 • Major System Terms for the numbers 000 – 999 • Freely customizable • Comprehensive collection of alternative Major System Terms • Choice of alternative images (camera, photo album, integrated web search for images) • Color codes for response times in the main view of the Major System • Cards view (comfortable learning like using file cards) • Optional extension to the three-digit major system (the trainer and the generator automatically use the chosen system: 2 or 3 digits) • Build optional major systems (in addition to the German, English and Italian Major System three custom major systems can be build) • CSV Import and Export • Import and export (incl. pictures) in Mnemo file format GENERATOR • Major System encoding for any numerical sequence • Possibility of adding notes • Saves any number of encodings • Settings (hide the notes field, hide the pictures, one or multiple terms per line) • Supports the Person – Action – Object (PAO) System (uses the optional master systems Custom 1, 2 and 3 alternately) Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://glab-apps.com/privacy.html

Screenshots

Decimal Rounding4 screens
Mnemo Major System Trainer4 screens

Verdict

The call

The clearest difference is rating: Decimal Rounding at 5.0 against Mnemo Major System Trainer's 4.4. Decimal Rounding also leads on price ($3.99 vs $12.99) and chart position (#191 vs unranked). Mnemo Major System Trainer's advantage is update cadence (every 2 months vs every 12 months) and ratings volume (18 vs 2). On ads, in-app purchases, monetization model and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Decimal Rounding costs $3.99 and Mnemo Major System Trainer $12.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Decimal Rounding holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: Mnemo Major System Trainer has 18 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 100% of Decimal Rounding's written reviews are positive against 88% of Mnemo Major System Trainer's.

UpkeepUpdate frequency

Decimal Rounding ships an update every 12 months, Mnemo Major System Trainer every 2 months. The most recent releases landed on October 8, 2026 and October 13, 2026 respectively.

Scorecard7 real differences · 4 level
Decimal Rounding versus Mnemo Major System Trainer: the parameters behind the verdict, then further details
ParameterDecimal RoundingMnemo Major System Trainer
Price$3.99 — better$12.99
Rating5.0 (2 ratings) — better4.4 (18 ratings)
Positive reviews100.0% of reviews — better88.1% of reviews
Number of ratings218 — better
Update frequencyEvery 12 monthsEvery 2 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
Best chart rank#191 — better—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.615.0 — better
Further details — not scored
Size1 MB54 MB
Age rating4++4
DeveloperEsa HelttulaGerald Reindl

Customer experience

Decimal Rounding

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Mnemo Major System Trainer

All ratings18 ratings
Positive77.8%
Neutral16.7%
Negative5.6%
Written reviews42 reviews
Positive88.1%
Neutral9.5%
Negative2.4%

In-app purchases

None

Decimal Rounding

No in-app purchases

None

Mnemo Major System Trainer

No in-app purchases

Questions

Is Decimal Rounding free?
Decimal Rounding costs $3.99, with no in-app purchases.
Is Mnemo Major System Trainer free?
Mnemo Major System Trainer costs $12.99, with no in-app purchases.
Which has better reviews, Decimal Rounding or Mnemo Major System Trainer?
Decimal Rounding is rated higher. Decimal Rounding averages 5.0 out of 5 from 2 ratings, while Mnemo Major System Trainer averages 4.4 from 18 ratings.
Do Decimal Rounding or Mnemo Major System Trainer have ads?
Neither Decimal Rounding nor Mnemo Major System Trainer shows ads.
Which is updated more often, Decimal Rounding or Mnemo Major System Trainer?
Decimal Rounding ships an update every 12 months, and Mnemo Major System Trainer every 2 months. Most recently, Decimal Rounding was updated on October 8, 2026 and Mnemo Major System Trainer on October 13, 2026.

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