NumberNinjasby iMentorKids
๐Ÿฅ‹ A math dojo for kids ยท Grades 3 to 7

Earn belts.
Battle bosses.
Master math.

Number Ninjas turns 3rd to 7th grade math into a game kids actually want to play. Pick the grade at sign-up. Daily training takes about 15 to 25 minutes; weekly boss battles earn belts; an endless Dojo, a weekly tournament, friend duels and career pathways keep them coming back when other apps wouldn't.

XP, coins & levels
Weekly boss battles
Weekly tournament
Friend duels
Factors
Fraction
Fraction Master
Decimals
Ratio
Proportion
Integer
Expression
Equation
Geometry
Exponents
Linear
Systems
Quadratics
Geometry II
๐Ÿงฎ
NEW

Now for younger ninjas: grades 3 to 4

Our new Foundations track builds the core skills (place value, addition and subtraction, times tables, fractions, decimals and money) that get younger kids ready for the belt program. Same belts, boss battles and rewards, pitched right at their level. Just pick the grade when you sign up.

A day in the dojo

About 15 to 25 minutes a day, four short blocks.

~15 to 25 min
Mental Math

5 quick-fire warm-up questions.

Core Lesson

Read the lesson, then 8 practice problems.

Data Log

Write down your score and one thing you noticed.

Tutor Track

Teach today's idea back in one sentence.

What's inside the dojo

A finite campaign to master, plus an endless arena that keeps even fast learners challenged.

Belt campaign

A 10-week journey for 5th to 7th grade math, plus a Foundations track for grades 3 to 4 and an advanced track climbing toward 10th grade. Earn a belt for each skill mastered.

Daily training

Four bite-sized blocks: a mental-math warm-up, a core lesson with practice, a data log, and teaching practice. About 15 to 25 minutes a day, with an energy meter that prevents over-grinding.

Boss Battles

Each week ends in a Boss Battle. Score 80% or more to earn the belt and unlock the next week, with unlimited pressure-free retries.

Endless Dojo

Once the day's work is done, the Dojo Challenge ramps up forever: faster, harder, 3 lives. Difficulty starts near your current belt so it's always a real challenge.

Weekly Tournament

Best Dojo run each week wins. Friends-only leaderboard, a Monday-to-Sunday race, and prizes that auto-pay when the new week starts.

Mental-math duels

Challenge a friend to a timed 10-question duel. Same questions for both, fastest correct wins. Kid-safe: friends only, no chat.

Career pathways

Pick a future-you (engineer, scientist, entrepreneur, game designer) and tackle hands-on mini-projects. Fresh randomized problems every replay, so it never gets stale.

Become a tutor

Finish the program to earn a Certified Tutor badge, then run a real tutoring business with built-in tools and a younger-kid Foundations track to teach from.

Choose your reward

Parents pick how prizes pay out: coins (default, in-app) or opt-in to Robux, V-Bucks, App Store gift cards, or cash. You set the amounts; the app tracks what's earned.

๐Ÿ’ธ
Free to play
Real-cash rewards are optional and parent-set.
๐Ÿšซ
No open chat
Kids can't message anyone, ever.
๐Ÿ”
Parent PIN gating
Parent Hub and friend approvals require your PIN.
๐Ÿ‘€
You see everything
An admin view shows signups, activity, and rewards owed.

Safe by design, parent-controlled

You approve every friend with a private parent PIN. There's no open chat anywhere, kids only see friends they're connected to, and the program is free to play. Donations are always optional.