Goblins vs. ST Math
Why we built Goblins
Goblins lets students speak and draw to learn math. That lets Goblin, the tutor, pinpoint exactly where mistakes and misconceptions arise. ST Math built a math program with no words in it. Goblins bets the other way, because a student who can say the math can keep it. The Gates Foundation funds Goblins.
“It forces them to really think about what they're doing and understand their process. ... They have to prove it. They have to show all of their work and it's been great.”
Renee Schuch · 6th Grade Math · Deer Valley
“Let's back this up to maybe something that we should have done two chapters ago. Do you understand this? Can you explain this? Okay, great. So from there, we're going to build on that and get back up to question number one.”
Rich Grell · HS Math Teacher, 22 yrs
“It's a little me in the computer. And it's like telling them, guiding them, questioning their thought processes. ... You have automatic homework help built into the program. And it's so powerful.”
Bobbye Graboyes · 26-year math teacher
Why not just use ST Math?
ST Math teaches without words on purpose, and that cuts both ways. The JiJi puzzles build genuine spatial intuition, and with no reading required every student can start. But the same design leaves a stuck student with no explanation path. A longtime curriculum reviewer found "no instructions or hints" for each new puzzle type, students left to trial and error, and recommends pairing ST Math with a program that teaches pencil-and-paper methods. Students say it more bluntly. A middle schooler's petition to drop the program, "gives ZERO instructions on how to do anything", gathered 475 signatures.
And the intuition does not reliably convert to achievement. The flagship test, a 2021 randomized trial across 52 high-poverty California schools and 16,307 students, found a gain of 0.04 standard deviations, under the threshold education researchers call small, and the ESSA-listed average across its studies is 0.07. A program that never asks students to say the math out loud leaves the hardest step to chance.
- No explanation path. A failed attempt plays an animation and the student retries. ST Math doesn't hear a student reason or watch them write.
- The marketed 0.35 effect comes from a non-randomized study's implemented-with-fidelity subgroup, a filter that keeps only the best-run rollouts. The same study measured 0.17 across all schools, and the randomized trials found 0.04 to 0.09.
- MIND's own 2025-26 roadmap doubles its library of Puzzle Talks, teacher-led discussion prompts that concede articulation matters, still nothing that helps the one stuck student mid-puzzle.
Thousands of Teachers ❤️ Goblins
"A kid who'd never do homework is now 100% in my class."
Rich Grell
HS Math Teacher, 22 yrs
"A little me in the computer, guiding them. So powerful."
Bobbye Graboyes
26-year math teacher
"They can't just Google it. They have to actually understand."
Renee Schuch
6th Grade Math · Deer Valley
"Stuck? It walks them back two chapters, then builds them up."
Rich Grell
HS Math Teacher, 22 yrs
"I can't split into 30. Goblins is 30 of me."
Bobbye Graboyes
26-year math teacher
"It forces them to fill the gaps and prove their work."
Renee Schuch
6th Grade Math · Deer Valley
"Like I'm sitting with every kid, and I can see who's faking it."
Rich Grell
HS Math Teacher, 22 yrs
"She did every Goblins assignment and aced the makeup."
Bobbye Graboyes
26-year math teacher
"I see who's stuck in real time and pull them aside."
Renee Schuch
6th Grade Math · Deer Valley
"The AI's on every question when I can't reach everyone."
Kaleb Bembenek
7th Grade Math
"I'd love to move my teachers from Study Island to this."
Carol Howe
Principal · Sharpsville Area HS
"It breaks down every misconception in real time."
Jenn Tifft
Math & Science
"It reaches every student I can't get to in person."
Rebecca Mello
Algebra I & II
"My kids customize the goblin to look like them."
Kaleb Bembenek
7th Grade Math
"I'd love to move my teachers from Study Island to this."
Carol Howe
Principal · Sharpsville Area HS
"It breaks down every misconception in real time."
Jenn Tifft
Math & Science
"It reaches every student I can't get to in person."
Rebecca Mello
Algebra I & II
Frequently asked questions
ST Math gives a stuck student no verbal instruction and no hints, by design. The puzzle animates why the attempt failed and the student tries again. A student who cannot infer the rule falls back to trial and error. MIND's teacher-led Puzzle Talks add class discussion around the puzzles, but the puzzles themselves don't hear a student reason or watch them write. Goblin treats the stall as its cue. It asks what the student was thinking, then draws a visual or a mini lesson right next to the problem, and it never just hands over the answer.
ST Math's independent randomized trials found effects too small to matter, and the 0.35 in MIND's marketing comes from a filtered subgroup that kept only the best-run rollouts. The number for all schools in that same study is half as large.
ST Math's recurring complaint is the missing explanation.
- A longtime curriculum reviewer found no instructions or hints for each new puzzle type and recommends pairing ST Math with a program that teaches pencil-and-paper methods.
- Students at one school petitioned to replace ST Math over the lack of instruction.
- Students and parents on review sites describe having no idea what a new puzzle wants.
ST Math starts at $3,500 a year for up to 150 students per school, per its published pricing listing on G2. Goblins teachers start free, no purchase order required.
Goblins is free for teachers, with 15 live help-enabled problems per student each month, worksheet uploads, standards-aligned assignments, and teacher avatars included, no credit card. Goblins Max, priced per school or district, makes live help unlimited and adds standards and engagement reporting.
ST Math sidesteps language with wordless puzzles, which works right up until a student needs an explanation. Goblins goes the other way. Students speak and draw in whatever language they think in, and Goblin keeps up. We never cap it at a number of languages, and we add new ones whenever a classroom asks.
Yes. The live classroom view shows every student's work as it happens, so you know who is stuck this minute and can pull a small group on the spot. Every problem rolls up against your state's standards with analytics you can export per student, per standard, and per skill.
Yes. Goblins complies with COPPA, FERPA, and student data privacy laws in all 50 states.
Weighing other options? See how Goblins compares.
Or see how schools run Goblins across intervention tiers in our MTSS math guide.