There is a particular kind of mathematics practiced by bored schoolchildren. It begins with a Chromebook, proceeds through a website whose name contains the word “math,” and ends, somehow, with a tiny car being driven up an impossible hill. Coolmath Games has lived inside that loophole for years. It is entertainment wearing sensible shoes. Sandbox Group, the London company that bought its parent in 2018, saw something larger in the joke: people are remarkably willing to learn when nobody announces that learning has begun.
That is the premise behind an odd-looking collection of businesses. PlayKids streams ad-free shows and games to young children. Leiturinha sends books through Brazilian letterboxes. Coolmath Games attracts puzzle players, many of them on classroom computers. Focus offers brain-training sessions to adults. Around them sits a wider family that has included Poptropica, Hopster, Tinybop, TeacherVision, Edujoy and Code Kingdoms. A portfolio like this could resemble a cupboard where acquisitions go to gather dust. Sandbox insists it has built the opposite: one platform, not a pile.
The collection started with an informed buyer
Bhav Singh knew the shelves he was buying. Before co-founding Sandbox with Abhi Arya in 2015, Singh had run Pearson English and Informal Learning. Earlier, he spent eight years expanding Viacom brands including MTV and Nickelodeon across emerging markets. Arya also came from Pearson's digital consumer business. Their first conspicuous purchase was Pearson's Family Education Network, whose properties included FamilyEducation, TeacherVision, Infoplease and Poptropica.
Poptropica was the useful clue. Created by Diary of a Wimpy Kid author Jeff Kinney, the children's adventure world was drawing an estimated 3.2 million monthly unique users in 200 countries and territories when Sandbox bought it. This was not a startup hunting for product-market fit. It was a place with rituals, memories and traffic. The founders' job was to make an existing habit travel farther.
“Can we build something of scale over the next five to 10 years?”Bhav Singh on his investment test
The sequence that followed is the company in miniature. Tinybop joined in 2016. Coolmath Games arrived in 2018. Sandbox took a majority stake in preschool service Hopster in 2019. Teachit followed in 2020; Edujoy, Tell Me Wow and Code Kingdoms in 2021; PlayKids, Leiturinha and toucanBox in 2022. Acquisition prices were usually not disclosed. Hopster described its 2019 round only as “multimillion-pound.” The important price, from Sandbox's perspective, was the work after the cheque.
and repeat use
billing and reach
next familiar screen
The real product is the route to the sofa
A children's app can be excellent and still vanish between the App Store and a parent's credit card. Sandbox treats that gap as a product problem. PlayKids now turns up on Prime Video, Samsung televisions and phones, VIZIO sets and telecom bundles. In Kenya, Safaricom customers were offered PlayKids+ for KES 20 a day. In Canada, Prime Video carries a localized English-and-French channel. Focus expanded into Canada, Romania and Spain through Digital Virgo's carrier billing. The company names more than 20 platform partners, including T-Mobile, Roku, Claro and Orange.
This is where Sandbox differs from a conventional edtech vendor. Schools are only one possible doorway. Parents, children and adults are the users; Amazon, Samsung and mobile operators are often the shop window and the till. Revenue can come from subscriptions, physical book clubs, advertisements, licensed content, add-on channels and carrier bundles. The catalogue changes by country because the payment habit changes by country.
Leiturinha supplies the most tactile example. The Brazilian club built six- and twelve-month installment plans around local credit-card economics. It has now shipped 30 million books, according to Sandbox, reaching more than 1.2 million families across 91 percent of Brazilian municipalities. The lesson is wonderfully unglamorous: global strategy sometimes means understanding why a bank guarantee makes a box of children's books easier to sell.
Then an old island lost its old address
The first thing to fail was not the central idea. It was some of the old machinery. Coolmath Games had to survive the death of Flash by converting games to HTML5. Poptropica later faced a more emotional version of the same problem. In 2024 its original web home was folded into Coolmath Games, and paid membership disappeared. Fans feared a shutdown. Sandbox described the move as preservation: one sister brand lending traffic and hosting to another.
Both versions can be true. Poptropica remained playable, including on mobile browsers, while its independent destination and parts of its old identity receded. Shared infrastructure rescued access; it did not recreate every island or promise a busy production slate. That distinction matters because a portfolio can make distribution efficient while making affection fragile. A beloved game is not merely a database that needs a cheaper server.
“We are building for value, not for valuation.”Bhav Singh, describing Sandbox's operating posture
AI changed the age limit
For most of its first decade, Sandbox spoke mainly to children, parents and teachers. The newer corporate language reaches farther. Its “Future Fit Skills” framework covers creativity, resilience, financial literacy, critical thinking, self-awareness and adaptability. Focus, launched into the portfolio's foreground in 2024, takes the group into adult cognitive training. In 2026, Learn Math by Coolmath Games pushed a familiar youth brand toward teens and adults.
What changed was the perceived shelf life of expertise. Sandbox argues that AI is making technical knowledge obsolete faster, leaving durable human capabilities more valuable. That is a thesis, not a clinical result. Yet it explains the strange age span of the current line-up: lullabies at one end, adult attention exercises at the other. The company no longer defines its market by the age of the learner. It defines it by a recurring need to practice being useful.
The figures above are downloads or stated platform size, not active users, so comparing them is like comparing library cards with books checked out. Still, they show why Sandbox can bargain for placement. A single unfamiliar learning app asks a carrier for a favor. A group bringing preschool shows, puzzle games, books and adult brain training offers a shelf.
The part worth stealing
There is a compact playbook here for anyone building a learning product. Begin with a behavior people repeat without coercion. Make the useful skill part of the mechanic rather than a lecture pasted on top. Centralize the plumbing users do not love - payments, localization, analytics, device support - and leave the beloved surface recognizable. Finally, distribute through places the customer already trusts. The remote control can be a more potent acquisition channel than another earnest landing page.
Four moves a smaller company can copy
- Measure voluntary return before celebrating lesson completion.
- Design the practice into the play loop, not into a pop-up quiz.
- Adapt payment and packaging to the market, down to daily carrier billing.
- Share infrastructure without flattening the brand people came for.
It will not work everywhere. “Learning by stealth” is poorly suited to regulated credentials, high-stakes assessment or subjects that require sustained instruction and feedback. A roll-up also fails when the brands have no repeat affection, when shared systems create more migration pain than savings, or when child-safety and privacy controls cannot survive expansion across jurisdictions. Even in entertainment, engagement is not proof of learning. The approach is strongest when practice itself creates value - a puzzle that exercises reasoning, a story that prompts language, a book delivery that builds a family ritual.
Sandbox's wager is ultimately about appetite. The education industry has spent decades improving the nutritional label. This company bought the snack aisle, then tried to improve the ingredients. Whether every product delivers on that promise is a question for evidence, parents and players. But as a theory of attention, it explains why a math-branded games site, a Brazilian book box and an adult brain app now belong in the same sentence.