Comparison

R21 vs Math Orbs

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

Head to head
About

R21

Features
Read full description

R21 is a new six-level reading series carefully designed to help young learners develop the skills they’ll need to succeed in the 21st century. Each book covers a range of topics and makes use of the latest Content and Language Integrated Learning (CLIL) methods to ensure they’ll appeal to young children and have a connection to children’s wider studies and experiences. With R21, reading is fun, inspiring as well as informative, and children will not only develop their reading competence but also become a great thinker in the 21st century.

About

Math Orbs

This app offers Grade 1-6 algebra practice for children, allowing parents to track progress and identify areas of difficulty. It features interactive quests, collectible orbs, and a virtual scratchpad for calculations, making learning engaging and eliminating the need for workbooks.

Highlights
  • Grade 1-6 algebra practice
  • Parental progress tracking
  • Identify areas of struggle
  • Interactive quests
  • Collectible orbs
  • Virtual scratchpad
Features
Read full description

Math Orbs is a math app that lets parents track their children's progress through Grade 1—6 algebra as they practice what they've learned. - Say goodbye to grading your child’s answers in workbooks! - Grades 1—6 algebra: never buy that “next grade” workbook again! - Scribbles for incorrect answers are recorded, helping you identify where and why they are struggling. - Track their overall progress and performance with statistics such as overall percentage score, time taken per quest, and time spent per question. Your kids will: - Practice Grade 1–6 arithmetic that becomes progressively more challenging, including addition, subtraction, multiplication, division, decimals, and fractions. - Unlock beautiful orbs every time they pass a quest. Try to collect them all! - Use the built-in virtual scribble pad for calculations—no paper or pencil needed! - No longer able to peek at the answers from the back of workbooks! Download Math Orbs today and help your kids become math wizards!

Screenshots

R213 screens
Math Orbs4 screens

Verdict

The call

The clearest difference is price: R21 at Free against Math Orbs's $0.99. R21 also leads on iOS requirement (9.0 vs 13.0). Math Orbs's advantage is update cadence (weekly vs every 3 months). On ads, in-app purchases 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

R21 is free to download; Math Orbs costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

R21 ships an update every 3 months, Math Orbs weekly. The most recent releases landed on October 10, 2026 and October 2, 2026 respectively.

Scorecard3 real differences · 6 level
R21 versus Math Orbs: the parameters behind the verdict, then further details
ParameterR21Math Orbs
PriceFree — better$0.99
Rating—5.0 (2 ratings) — better
Number of ratings—2 — better
Update frequencyEvery 3 monthsWeekly — better
AdsNoNo
In-app purchasesNoNo
Monetization—Paid
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS9.0 — better13.0
Further details — not scored
Size114 MB72 MB
Age rating4+4+
DeveloperCAVES BOOKS LTD.Knowledge Vortex, LLC

In-app purchases

None

R21

No in-app purchases

None

Math Orbs

No in-app purchases

Questions

Is R21 free?
R21 is free to download, with no in-app purchases.
Is Math Orbs free?
Math Orbs costs $0.99, with no in-app purchases.
Do R21 or Math Orbs have ads?
Neither R21 nor Math Orbs shows ads.
Which is updated more often, R21 or Math Orbs?
R21 ships an update every 3 months, and Math Orbs weekly. Most recently, R21 was updated on October 10, 2026 and Math Orbs on October 2, 2026.

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