• The basics
All you need to know if you have 20 seconds.
• Insertion
How to insert something in the middle of an expression.
• Selection by group
How to quickly select the parenthesis (or bracket) as a whole.
• Inspect
Check the result for part of your expression.
• Summary of shortcuts
Yes you can do it all via the keyboard.

Most of our editing involves correcting a number.
And Magic Number makes this fast and easy.

# With the mouse

Just click the part you want and type over it.

# With the keyboard

You can use the left and right arrow keys:

,

The tab key takes you to a number quickly:

You can insert with option-left or option-right:

or

If you prefer the mouse, just click:

The first and last arrows are for insertion.

In writing, we have words, sentences, and paragraphs.
In math, we have expressions formed by ‘groups’ of elements.

The most obvious kind of group is the bracket (parenthesis).
It literally groups elements together.

To select it as a group, double-click either (  or  ).

You can also press ⌘G.

Like editing text, it’s easier to double-click to select a word.
In Magic Number, double-clicking is faster and more intelligent.

As Magic Number understands the structure of your expression, it knows
how the elements are grouped. Therefore it can offer meaningful selection.

## The other groups

Mathematically  2 + ( 3 × 4 )  is equivalent to  2 + 3 × 4. They yield the same result. The higher precedence of multiplication bonds with 3 and 4 to form a group.

You can double-click the operator ‘×’ to select the group:

If we have division ‘÷’ instead of ‘×’, the expression becomes  2 + 3 ÷ 4,
and 3 ÷ 4 as a group is more apparent as we see it as a fraction:

So operator is a group. This includes √ and functions like sine.

Tip: You can double-click a member to select its group.
For example double-click 3 to select the whole fraction.
(⌘G works the same way.)

## Group of a group

The ‘+’ operator is also a group. It consists of 2 and the group 3 ÷ 4.
You can verify this by double-clicking:

So an expression is just a group of groups.
You can also think of a group as a sub-expression.

## Sucessive selecting

To illustrate, let’s enter an expression with mixed fraction 1 + 2 & 3 ÷ 4

Triple-click 3:

Or press ⌘G sucessively:

#### Exercise:

Press ⇧⌘A to deselect. Then click 3 sucessively for 4 times.
Notice how each successive click selects the parent group.

## Why select by group?

• You can delete it as a whole.
• You can replace it with a new value.
• You can bracket your selection with ⌘].
• You can inspect your selection.

You can see the value of your selection by pressing ⌘I.

Let’s examine the value of  82 + 152

You can simply select ‘+’, press ⌘I, Magic Number will automatically select its group and show you the value.

Another trick, you can inspect memory, tax rate, or constant:

Notice tax is automatically selected because it is near the cursor.

The arrow keys let you go to and select the element.
This makes it easy to do corrections.

 ▶ Select next ◀ Select previous ⌘ ▶ Select last ⌘ ◀ Select first

When you press ⌥, the insertion cursor goes to that item.

 ⌥ ▶ Go next ⌥ ◀ Go previous ⌥ ⌘ ▶ Go last ⌥ ⌘ ◀ Go first

As you can see command (⌘) takes you to the beginning or end.