A notebook for working problems out a step at a time. Everything you type stays on this device.
Writing math
Ctrl + M, or the Insert math button, drops a math box wherever the cursor is.
Inside a box, Enter starts another line in the same box. That is how you stack the steps of one problem. Shift + Enter leaves the box and goes back to plain text.
Type \ inside a box for commands: \frac, \sqrt, \theta, \int.
Drag the ⠿ handle to the left of an expression to move it. A caret shows where it will land.
Checking your work
Switch on Check in the toolbar. Every line in a box is compared against the first one. ✓ means the two still match, ✗ means the value changed somewhere, ? means it could not tell.
Equations are compared by their solutions, so solving down to x = -1 counts as a match. Multiplying or dividing both sides, distributing and combining fractions all pass. Squaring both sides does not, because it invents a solution you did not have.
An amber ✓ is the in-between case: the step follows, but it has fewer solutions than the line above. Usually that means you divided by something that can be zero.
The check samples both lines at random values instead of doing symbolic algebra, so a ✓ means no counterexample turned up, not that a proof exists.
Simplifying and rearranging
Double-click any fraction, root or power: 12/18 becomes 2/3, √72 becomes 6√2, 4³ becomes 64. One click on the pill that appears does the same thing. It takes two deliberate clicks so you cannot set it off by brushing past.
Ctrl + . simplifies every part of the box at once. Ctrl + S takes the line you have highlighted and writes the arithmetic out on the line below.
Ctrl + F factors the current line. Ctrl + G multiplies the brackets back out.
Each of these leaves an Undo in the toast at the bottom.
Drawing on the page
Draw turns the marker on and you can write anywhere on the sheet, over the top of your typing. Pick a color and a thickness from the bar that appears.
The eraser removes whole strokes. Clear wipes the page, and Esc or Done puts the marker away so you can type again.
The calculator
It is a list rather than a single display: each row works itself out as you type and there is no equals key. Enter starts the next row.
Name a value in one row (a = 12) and use it further down. ans is the row above.
DEC / EXACT switches between decimals and exact fractions, radicals and multiples of π. ℝ / ℂ allows complex numbers, so √(-4) gives 2i rather than an error. RAD / DEG sets the angle mode for the trig keys.
Click a result to use it again. ↗ sends a row into your notes, and Send selection pushes highlighted notes the other way.
Triangles and formulas
Triangle inserts a place to keep sides a, b, c and angles A, B, C together. Fill in what you know. It never calculates anything, it just stops you losing track. Hover it and click × to remove it.
The Formulas tab holds 43 algebra, trig and calculus formulas with a search box. Click one to drop it into your notes.
Tabs, saving and sharing
Tabs sit above the page. + adds one, double-click to rename, ✕ closes.
Your work saves itself to this browser as you type. Save keeps a snapshot you can reopen from Open.
Share copies a link with the entire workspace packed inside it. Nothing is uploaded — the work travels in the link. Settings also has Export and Import if you would rather have a file.
Setting it up
Settings covers the paper (blank, ruled, grid or dots, on five surfaces), the ink, and the size, face and width of your text. The ink color runs through the whole app, including the lines printed on the paper.
You can also move the calculator to any edge, resize its keys, and switch off keys you never press so the rest get more room.
On a phone the calculator is a sheet: tap the floating button to open it, then × or the space above it to close.
Shortcuts
- Insert a math box
- CtrlM
- New line inside the box
- Enter
- Leave the box
- ShiftEnter
- Work out the highlighted line
- CtrlS
- Simplify everything in the box
- Ctrl.
- Factor the line
- CtrlF
- Multiply the brackets out
- CtrlG
- Undo
- CtrlZ
- Save a snapshot
- CtrlShiftS
- New workspace
- CtrlAltN
- Put the marker away
- Esc