01 / SOLVE
You solve the problem.
111sm · POWERED BY FULLMO
Maths. Solve. Review.
Choose a paper or topic, practise at your own pace, and review with hints and explanations. Free to start.
Built by
TRINITY EDULAB / Sungmin Kim mathematics teacher. We build a mathematics training app for high school students.
- Starts without a sign-in
- No name, school, or phone number
- Sign in for handwriting grading and account records
Signed-in demonstration, 8 September 2026: the app extracts 6 from handwritten a+b=6. We confirm it without editing, then mark and save the work. Marking compares the confirmed final value with the answer key. Demonstration work, with waiting time cut and desktop footage reframed for mobile.
Open video file ↗02 / WHY AGAIN
There is a reason the same problem comes back wrong, no matter how much you solve.
Solve, grade, read the explanation, move on. In that routine, neither the reason for the mistake nor the way you worked reaches the next session. The reason stays in your head, and a few days later a similar problem stops you in the same place.
02 / GRADE
You grade it and read the explanation.
03 / MOVE ON
You move on. The work and the pattern behind the mistake are gone.
Mathematical skill is not only how many problems you solve. It changes with what you record after a mistake and how you train it again.
03 / WHAT IT DOES
Not another problem bank. A training structure where the record and the review connect.
Only what the app actually provides is listed here. Every screen is the real 111sm.app.
01 / PRACTICENo sign-in Real exam practice
Find and solve a large archive of past math exams by paper, unit, or question number, then check with hints and explanations.
Real 111sm.app screen / Captured 2026-09-05The mathematics shelf. Choose by curriculum, school year and paper, or find a unit or question number. 02 / HANDWRITINGAfter sign-in Handwriting grading on the question
Write on the question and choose Read handwriting. Check or correct the value before submitting it. The app compares the confirmed final value with the answer key and saves your work to your account. Sign-in is required.
Real 111sm.app screen / Captured 2026-09-04The practice screen. Write on the question, mark an option, and keep going with the timer. 03 / REVIEWAfter sign-in Mistake review
Missed questions stay in your account so you can pull only those out and solve them again. Miss the same one again and it shows which time that is.
04 / DAILYNo sign-in Practice at your own pace
Choose a paper or topic, then solve and check one question at a time without signing in. You do not need to finish a whole paper.
Real 111sm.app screen / Captured 2026-09-04The math flow screen. Solve alone first, get a hint when wrong, then ask. Solving needs no sign-in.
04 / HOW IT WORKS
One session leads into the next.
What a student sees and does in the app, in order.
- 01 / PRACTICE
Choose what and how to practise
Browse papers and topics, choose one-question practice or a full paper, and start when you are ready.
No sign-in→ - 02 / HANDWRITE
Keep the handwritten work
Write directly on the question. After sign-in, confirm and submit the answer read from your work to save that solution separately from the paper result.
After sign-in→ - 03 / CHECK
See what went wrong
Check the result. For an incorrect answer, read the hint and then open the worked solution.
No sign-in→ - 04 / REVIEW
Review the missed questions
In the mistake notebook, see the option you chose next to the answer and explanation, and jump straight to your handwritten work for that question.
After sign-in→ - 05 / REPEAT
Train again
Solve only the missed questions again, then continue with past questions from the unit you miss most.
After sign-in→ - 06 / RETRY
Back to a full set
Try the next paper under exam conditions. Account records show how often you have missed the same question.
No sign-in
05 / WHAT CHANGES
When the missed questions are visible, the way you study changes.
A student who used to guess at weaknesses now confirms them from the record and trains only what is needed. The evidence is the real app screen.
Until now
- Weak spots are a guess
- A mistake notebook exists but is never solved again
- The working is thrown away with the paper
- A problem solved alone has no other solutions to compare
In 1일 1실모
- Missed questions stay in the account record
- Only those come back out, with the count of misses
- Work submitted for handwriting grading stays in the account
- Other solutions to the same question are there to compare
The mistake notebook and the handwriting archive appear only after sign-in, so only screens available without a sign-in are shown here.
06 / FAQ
Questions before you start
Open a question to read the answer.
01Who is it for?
High school students who solve math problems regularly but keep missing similar ones. Especially those who never managed to sort out their weak types, or who keep a mistake notebook they never solve again.
02What problems are in it?
Published past math exam questions from the national exam and mock exams, selectable by paper, unit, or question number. Hints and explanations come with them, and more past papers keep being added.
03Which devices does it run on?
It runs in the browser with nothing to install. It is built for a tablet in landscape, and works on a phone or laptop for solving and reading your record. Handwriting on the question is most comfortable with a tablet and pen.
04Does it cost anything?
Solving, hints and explanations, and mistake review are free. Handwriting grading has a daily limit on free accounts. The guided process, where the teacher and assistants comment directly on your handwriting and mistake notebook, is explained separately and can be requested through the trial application on this page.
05Where does my record live?
Answers in progress and time spent may stay temporarily in this browser. After a full paper, you choose whether to save its result to an account; some unit and question drills do not save paper results. Handwriting is saved separately when you confirm and submit the answer after sign-in. Unsaved writing can disappear when you change questions or refresh.
06What does handwriting grading check?
It reads your handwriting and suggests an answer. You confirm or correct the value before submitting it for comparison with the answer key. It does not check every step of your reasoning. If the writing is unclear or the format is unsupported, check the value yourself before submitting.
07What does signing up require?
You sign in with a Kakao or Google account, confirm that you are 14 or older, and agree to the privacy policy. No name, school, phone number, or date of birth is collected.
08How can I ask about a consultation or trial?
Send an enquiry through 1:1 chat on our KakaoTalk channel. You can decide after discussing the format and schedule in the reply. Email is also available.
TRINITY EDULAB
One purpose. A clear role for each service.
111sm is our main high-school maths service. Concept exploration, overseas preparation and the founder’s teaching and writing each serve a distinct need.
Main service · High-school maths in Korea
111sm
High-school maths, from practice to review. Choose a paper or topic and practise one question at a time or as a full paper, without signing in.
Explore maths practiceComplementary · Concept exploration
maths.study
Explore concepts through a 3D world or a 2D map, answer questions and find a route for your next study session.
Explore the concept mapOverseas · Institutional pilot proposal
Trinity Admission
College Ready proposes four weeks of maths and writing preparation for university study. The programme page distinguishes working demonstrations from proposed services.
Explore College ReadyFounder · Teaching and writing
mathskim
Sungmin Kim’s personal brand. Two free books and a maths question channel introduce the thinking behind the teaching.
Meet the teacher and author07 / START
Start solving, or ask about a guided trial.
START NOW
If you want to start right now
Explore papers and topics, then practise without signing in. Sign in to save results or request handwriting grading.
Explore maths practice 1일 1실모 / powered by FULLMO / Public beta · FreeGUIDED TRIAL
If you would like guidance
Get in touch through the Trinity MathsLab KakaoTalk channel. Discuss the available options and schedule in the reply.
Ask about a trial on KakaoTalk →Open the channel, choose 1:1 chat, and send your enquiry. Arrange a time after receiving a reply.You can also get in touch by email.sungmin.t@maths.study