Getting started

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This guide covers essential skills you need to get started with the Math I Can Do math editor. With a little practice, you will be able to write math two, three, or more times faster than you can write it by hand—and with fewer mistakes, too!

Writing basic math

You can write many elementary math expressions just by typing.

To write:

$3 x + 2 = 8$

Just type:

3 X + 2 = 8

Tip: As you work, you may notice that a bubble sometimes pops up with a suggestion. This is part of a feature called abbreviations. We will learn about these later; for now, just know that pressing Space (or clicking the bubble) will perform the suggested action.

Multiplication and division

Multiplication is commonly represented with two different symbols, a dot or a cross. Type * once for a dot ( $\cdot$ ) symbol and twice for a cross ( $\times$ ) symbol.

To write:

$2 \cdot 2 = 4$

Type:

2 * 2 = 4

To write:

$0 \times n = 0$

Type:

0 * * N = 0

You can get a $\div$ division sign by typing \, but outside of elementary arithmetic, you probably want a fraction instead. To create a fraction, type the numerator (top part), press /, type the denominator (bottom part), and press Enter:

To write:

$\frac{1}{2}$

Type:

1 / 2 Enter

The editor infers the numerator from what comes before the /. It will include most content, including numbers, variables, exponents, and radicals. It stops at binary operators (like $+$ ). To write a fraction including elements that the editor will not include in the numerator automatically, select the desired numerator before pressing /. Or, insert an empty fraction by typing Ctrl + /.

To write:

$\frac{x + 2}{4}$

Type:

Ctrl + / X + 2 Enter 4 Enter

Inequalities

To get an inequality like $<$ , type the symbol normally. If you then type =, the symbols combine to give $\leq$ . Similarly, typing = = gives $\neq$ .

Exponents

To attach an exponent to what you just wrote, type ^, then write the exponent, then press Enter:

To write:

$x^{2}$

Type:

X ^ 2 Enter

Using ^ works for any exponent, but a common case is writing a polynomial term like $x^{4}$ . As a shortcut, typing a variable, an integer, and then pressing Space turns the integer into an exponent. In fact, the editor often predicts the exponent for you.

To write:

$4 x^{3} + x^{2} + 1$

Type:

4 X 3 Space + X Space + 1

Brackets

To write an expression in round brackets (parentheses), type (, then write the expression and press Enter. The matching ) is created for you, so the numbers of left and right brackets always match up.

To write:

$x - (3 x - 2)$

Type:

X - ( 3 X - 2 Enter

Square brackets work the same way: just type [ instead of (.

Tip: Besides pressing Enter, you can also leave brackets by typing the matching closing bracket key, ) or ]. These commands will move the insertion point (where typing appears) out of the nearest brackets of that type.

Functions

Don’t use ( for functions like $f (x)$ . The editor always treats brackets as brackets, so you’re saying that you want to multiply $f$ and $x$ . Instead, use the $()$ button in the Functions panel beside the editor.

Because functions are so common, you can enter them quickly using an abbreviation. To create an empty function object, you can type F N Space. Typing one or two extra letters before the space will fill the details in:

To write:

$g (y)$

Type:

F N G Y Space

Or just type one letter for functions named f. To write:

$f (x)$

Type:

F N X Space

Matrices

To insert a matrix, you can press Alt + [. You don’t need to choose a size ahead of time. Matrices grow automatically when you type in the rightmost column or bottomost row. (These special edge elements are not really part of the matrix. They disappear when you move to a new line.) To move from cell to cell, press Enter. At the end of a row, press Enter twice to skip to the next row. You can leave the matrix from any cell by pressing ].

To write:

$[\begin{matrix} 1 & 0 \\ 0 & 1 \end{matrix}]$

Type:

Alt + [ 1 Enter 0 Enter Enter 0 Enter 1 ]

Changing an equation in steps

Equations are often developed in a series of steps: each line is similar to the previous line, but with one key change like moving an expression out of parentheses. The Duplicate line command makes it easy to write math that follows this pattern. Whenever you complete a step, press Ctrl + D and an exact copy of the current line will be inserted above. Now just continue editing until you have reached the next step and repeat.

Splitting and joining lines

In a regular text editor, you can split a paragraph in two by pressing Enter. Likewise, you can join two paragraphs up by moving to the start of the second one and pressing Backspace. When writing math, that kind of editing doesn’t usually make sense. To keep you from doing it by accident, it’s a little harder: lines won’t split or join up unless you are also holding Ctrl while pressing Enter, Backspace, or Delete.

Working with fields

Some math objects have fields. A field is just a box that expects to have some math written in it. You’ve already seen examples: fractions, exponents, and parentheses all use fields. You’ve also already learned the most important key for working with fields: Enter. At the end of a field, this key moves the caret out of the field. Otherwise it moves the caret to the end of the field.

The way fields work makes editing easier. For example, the selection commands Shift + ← Left and Shift + → Right stop at field edges, so you can hold them down without selecting more than you mean to. Similarly, Delete and Backspace stop at the field edge unless the entire field is empty. You can quickly erase part of a field by just holding a key down, without worrying about deleting too much.

Tip: Some math objects include optional fields, which have dotted grey outlines when empty. As the name suggests, it is OK to leave these blank.

Growing selections outward

Selections can’t be split across fields, but they can grow outward to cover the entire object that contains that field.

To grow the selection outward from the insertion point, use:
Select more Shift + ↑ Up

To shrink the selection inward back towards the insertion point, use:
Select less Shift + ↓ Down

If there is no selection, or if the selection doesn’t cover the entire field, then Select more will select the entire field. If the field is already selected, then it will select the object that the field is a part of.

Quickly selecting the object containing a field is an important technique. There are a number of commands that operate on the selected object. For example, you can take the reciprocal of the fraction that contains the insertion point by using Select more twice, then using the Take reciprocal command, Ctrl + R.

Unwrapping, wrapping, and changing things

It is common to have to replace an object with its contents. For example, to simplify an expression with brackets, the contents of the brackets need to be moved out of the brackets and the brackets deleted. In the editor, this is called unwrapping the brackets. To do it, select the brackets (or other object) and then use the Unwrap command, Ctrl + U.

Creating an expression with brackets:

$(x + 2)$

( X + 2 Enter

Then selecting and unwrapping the brackets:

$x + 2$

Shift + ← Left, Ctrl + U

Besides unwrapping some math, it is also common to have to wrap it up. The current selection can be wrapped in an object by pressing that object’s keyboard shortcut.

Suppose that you are writing $(x + 2)$ but forgot to start with (:

$x + 2$

X + 2

To fix this you could select and then wrap the expression:

$(x + 2)$

Shift + ← Left × 3, (

Or alternatively:

Shift + Home (

Tip: By unwrapping and then rewrapping, one math object can be changed into another. For example, you could unwrap square brackets and then rewrap in round brackets to change an expression from square to round brackets. For common changes of this sort, you can right click on the math object and then choose the kind of object you want to convert it to.

Abbreviations

There are too many math objects for each to have a keyboard shortcut. To get around this, every math object has an abbreviation. An abbreviation is a short sequence of characters. If you type an abbreviation and press Space, the abbreviation is replaced by its math object.

To write:

$x \in {x, y}$

You can type:

X I N Space { X , Y Enter

This works because in is the abbreviation for the $\in$ (element of) object.

Tip: When an abbreviation is recognized, a bubble appears near where you are typing that will show you what to expect if you press Space.

Conflicts

When expanding an abbreviation, the editor will choose the longest abbreviation it can. For example, if we had typed sin instead of xin, it would have expanded to the sin() function. In these cases, you can mark where you intend the abbreviation to begin with a decimal point.

To write:

$s \in$

Instead of:

$\sin ()$

You can type:

S . I N Space

It’s always OK to use a decimal point, even if it isn’t required.

Guessing

Each math object has a specific assigned abbreviation that always matches that object. When you know what you want but not its abbreviation, start typing the name and the editor will try to guess what you are looking for. For example, the abbreviation for $\exists^{1}$ (there exists one) is ex1. But if you type existsOne (or even exiO), the editor can guess what you mean. Unlike assigned abbreviations, guesses are predicitve: if what you type matches more than one object, the editor may guess differently depending on what math is nearby.

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