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Apply the identity properties

The additive identity is 0 because adding 0 to any whole number leaves its value unchanged, and the multiplicative identity is 1 because multiplying any whole number by 1 leaves its value unchanged: n+0=0+n=nn+0=0+n=n and n×1=1×n=nn\times1=1\times n=n. This understanding supports simplifying numerical expressions and distinguishes multiplication by 1 from multiplication by 0; at this level, it is limited to whole-number addition and multiplication, not identities for other operations or abstract algebraic systems.

Detailed Explanation: Apply the identity properties

An identity is a number that leaves another number unchanged when you use it in an operation.

  • For addition, the identity is 00:
n+0=nand0+n=nn+0=n \quad\text{and}\quad 0+n=n
  • For multiplication, the identity is 11:
n×1=nand1×n=nn\times1=n \quad\text{and}\quad 1\times n=n

Example

Simplify:

24+0+6×124+0+6\times1

Step 1: Use the multiplicative identity.

Since multiplying by 11 does not change a number,

6×1=66\times1=6

The expression becomes:

24+0+624+0+6

Step 2: Use the additive identity.

Since adding 00 does not change a number,

24+0=2424+0=24

Now the expression is:

24+6=3024+6=30

So,

24+0+6×1=30\boxed{24+0+6\times1=30}

Remember: adding 00 keeps a number the same, and multiplying by 11 keeps a number the same. Multiplying by 00 is different because it makes the product 00.

Learn by doing: Apply the identity properties

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