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Decimal numbers are numbers that have a decimal point followed by digits that depict the fractional part. The number of digits determines the number of decimal places.

Basic operations on decimals are addition, subtraction, multiplication, and division.

- Step 1: Ignore the decimal point and multiply the two numbers as usual.
- Step 2: Count the number of decimal places in the decimal number after multiplication. The number of decimal places in the product received after multiplication will be the same.
- Step 3: Write the decimal point in the obtained product in Step 2.

Find 13 x 7.5.

Answer: 97.5

Find 1.3 x 7.5.

Answer: 9.75

Shift the decimal point to the right as many places as the number of zeros in the power of 10 when multiplying any decimal by 10,100,1000, etc.

1.73 x 10 = 17.3

1.73 x 100 = 173

1.73 x 1000 = 1730

Divide decimals by whole numbers the same way we divide whole numbers. A divisor is a whole number, and the dividend is a decimal. Thus, the quotient will have the same number of decimals as the dividend.

Note: To divide a decimal number by a decimal number, multiply the divisor by as many tens as needed until you reach a whole number. Then, multiply the dividend by the same number of tens.

Divide 7.68 by 3.

Answer: 2.56

When a number is divided by 10, we move the decimal point 1 place to the left.

86.5 10 = 8.65

When a number is divided by 100, we move the decimal point 2 places to the left:

876.345 100 = 8.76345

When a number is divided by 1000, we move the decimal point 3 places to the left.

987.5 1000 = 0.9875

Note: When there is no digit in the one’s place, we write 0 as a placeholder.

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