Identity Property of Multiplication

Identity property of multiplication:

a×1=a\color{purple}{a\times 1=a}

What does it mean?

It means, that multiplication of the number with one will result in original number.

Recall, that multiplication is shorthand for addition.

a×1a\times 1 means, that we use aa one times. In other words, we are left with original number aa.

Using commutative property of multiplication, we can write that a×1=1×a{a}\times{1}={1}\times{a}.

Thus, a×1=1×a=a\color{purple}{a\times 1=1\times a=a}.

This is also true, if we divide by one: a1=a\frac{a}{1}=a.

In fact, identity property is true for any real number.

Example 1. 3×1=3{3}\times{1}={3}.

Example 2. (2)×1=2{\left(-\sqrt{{{2}}}\right)}\times{1}=-\sqrt{{{2}}}.

Example 3. 1×58=58{1}\times\frac{{5}}{{8}}=\frac{{5}}{{8}}.

Conclusion. Multiplication or division by 1 doesn't change things.