Decimals | Year 7 Mathematics (Cambridge) PDF Download

Decimal Place Value

Understanding decimal place value is crucial for working with decimals effectively. Each digit's position relative to the decimal point indicates its value.

• Tenths: The first digit to the right of the decimal point represents tenths.
  • Example: In 0.3, '3' is in the tenths place, representing
• Hundredths: The second digit to the right of the decimal point represents hundredths.
  • Example: In 0.24, '4' is in the hundredths place, representing
• Thousandths: The third digit to the right of the decimal point represents thousandths.
  • Example: In 0.125, '5' is in the thousandths place, representing

Operations with Decimals

Performing operations like addition, subtraction, multiplication, and division with decimals involves specific rules and methods.

• Addition and Subtraction: Align decimals vertically and add or subtract as with whole numbers after lining up the decimal points.
  • Example: 3.7 + 1.24 = 4.94
• Multiplication: Multiply the numbers as if they were whole numbers, and then adjust the decimal point in the product based on the total number of decimal places in the factors.
  • Example: 2.5 × 1.2 = 3.0
• Division: Perform division as usual, but adjust the decimal point in the quotient based on the number of decimal places in both the dividend and divisor.
  • Example: 4.8 ÷ 1.5 = 3.2

Examples

Example 1: Decimal Place Value
Number: 0.47
Tenths place: 4 (represents )
Hundredths place: 7 (represents )

Example 2: Addition
2.3 + 1.56 = 3.86

Example 3: Multiplication
3.7 × 0.5 = 1.85