Logic literacy
Build the steps out of blocks and run them in the open, where you can watch every value move and every decision light up. Same input, same answer, every single time.
Here is a real board, stopped one step before it decides. Read it, then call it.
Read the board above, then answer
A price of 240 came in, so total is 240. Look at the diamond. Which way does total > 100 send it?
no signup, nothing to install
01 · See it think
Values reduce one step at a time. Conditions light clause by clause. Every value wears its type. If the engine did not do it, the screen does not show it. Every animation targets a documented novice misconception.
fig. 1 · every expression, one step at a time
fig. 2 · short-circuit, shown honestly
fig. 3 · text glues, numbers add, the trace says which
fig. 4 · same blocks, different place, different answer
Most tools tell you the result. voltabench shows the reasoning.
02 · Why now
It killed the tedious half and left the half that mattered. The same trade is running against code right now. Worth being precise about which half is leaving.
It killed long division; number sense survived. Syntax is dissolving into the tools the same way. What survives is saying exactly what you want and knowing the answer is right.
The evidence
A thousand students, three groups. One got plain ChatGPT, one got a tutor built to give hints instead of answers, one got a textbook. While the AI was on screen both AI groups pulled far ahead. Then it was taken away and everyone sat the same exam.
Call it before you scroll
On that exam, with no AI in the room, how did the plain ChatGPT group do against the students who had only ever used a textbook?
We built this because something has to make you do the thinking, and an engine that runs whatever you actually specified does that on its own, with nobody standing over you. The oldest finding in the field found the same thing. Across 24 experiments, how students use a visualisation matters more than what it shows them. The activity they list first is predicting what happens next.
The engine does exactly what you say. That is how you learn to say exactly what you mean.
Sources
Only the first is charted. The others are smaller, self-reported, or qualitative, and sharing an axis would lend them a precision they do not claim.
03 · It transfers
Boxes, arrows, and diamonds are already how science, business, and engineering write decisions. Here the diagram is not a picture of the logic. It is the logic, running live. Learn it once and the skill leaves the tool.
Not a block language. Scratch and Blockly teach the shape of program text. This is the notation the working world already writes decisions in, running for real.
All product names are trademarks of their respective owners. voltabench is not affiliated with or endorsed by them.
04 · For instructors
Define correctness once, as data. Every submission is graded against the same cases, and every grade opens into evidence a student can read.
A zero is explainable in one minute: open the grade, read the failed case, see expected next to actual.
A complete course ships with it: 37 assignments, from first output to loops, each with a reference solution and graded cases. Teach it as-is on day one, or adapt any piece of it.
Deadline control that matches real life: reopen for one sick student or the whole class, from one roster.
See who has not submitted, by name, straight from the assignments list, and a gradebook with CSV export.
Student work stays the institution's: submissions and grades are your education records, and no AI ever touches them. Full detail in the privacy policy.
05 · Before you ask
Answered the way we would answer them in an email.
Those teach the shape of program text: blocks that snap like statements and nest like code. A good on-ramp to writing it. voltabench runs the notation the world already writes decisions in. Boxes, arrows and diamonds are older than the computer, and medicine still writes triage that way, and business still writes approvals that way. What we add is the engineering underneath: values that carry their type, runs that are the same every time, and answers checked against real cases.
No. You build logic out of blocks and watch it run. No syntax, no setup, nothing to install.
No. It runs in the browser, on a laptop or an iPad, and your work saves as you go.
Signing in with Google is one way to create your voltabench account. It reads your name, email address, and profile picture, and nothing else. Your email is matched against your course invitation so you land in the right class; your name and picture appear on your own dashboard and on your instructor's roster. Nothing is written back to your Google account, and none of it is sold or shared. Full detail in the privacy policy.
No. The engine is deterministic: same input, same answer, every time. Nothing here guesses, and nothing grades you by vibe.
Adopt the included course, 37 assignments with graded cases, or bring your own. Invite your roster, done. Correctness is test cases, applied identically to every submission.
Small enough that we can answer every email while we learn what actually helps. Fall 2026, free for students.
The bench is open
A gym for logic: expression, construction, and testing. Free for students, invitation only, Fall 2026.
Request an invitation →