Decimal Operations Math Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

medium
Multiply 0.45×0.80.45 \times 0.8 and explain how to place the decimal point.

Solution

  1. 1
    Ignore the decimals and multiply whole numbers: 45×8=36045 \times 8 = 360.
  2. 2
    Count decimal places: 0.450.45 has 22 and 0.80.8 has 11, total =3= 3 decimal places.
  3. 3
    Place the decimal in 360360: count 33 places from the right ⇒0.360=0.36\Rightarrow 0.360 = 0.36.

Answer

0.360.36
When multiplying decimals, the number of decimal places in the product equals the total decimal places across all factors. Multiplying as whole numbers first and then placing the decimal avoids confusion.

About Decimal Operations

Decimal operations — addition, subtraction, multiplication, and division — follow the same rules as whole-number arithmetic but require careful attention to decimal point placement and alignment.

Learn more about Decimal Operations →

More Decimal Operations Examples

Example 1 easy

Add [formula].

Example 3 easy

Subtract [formula].

Example 4 hard

A 3-metre length of rope is cut into pieces, each [formula] m long. How many complete pieces can be

Example 5 medium

Calculate [formula].

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