Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Understanding Decimals: A decimal number consists of a whole number part and a fractional part separated by a dot called the decimal point. For example, in , is the whole number and represents the part of a whole.
The Tenths Place: When one whole is divided into equal parts, each part is called one-tenth. Visually, imagine a rectangular bar divided into equal vertical strips; shading one strip represents or . It is the first digit to the right of the decimal point.
The Hundredths Place: When one whole is divided into equal parts, each part is called one-hundredth. Visually, imagine a large square grid made of rows and columns (total small squares); shading one tiny square represents or . It is the second digit to the right of the decimal point.
Place Value Chart: To the left of the decimal point, we have Ones, Tens, and Hundreds. To the right, we have Tenths () and Hundredths (). Moving one place to the right divides the value by , while moving one place to the left multiplies it by .
Reading Decimals: We read the whole number part normally, say 'point' for the decimal, and then read each digit to the right individually. For example, is read as 'Four point seven five' or 'Four and seventy-five hundredths'.
Expanded Form: Decimals can be broken down into the sum of the values of their digits. For example, is written as or .
Equivalent Decimals: Adding zeros to the right of the last digit in a decimal does not change its value. For instance, is the same as , which can be visualized as tenths of a bar being the same area as hundredths of the same bar.
📐Formulae
💡Examples
Problem 1:
Write the place value of the underlined digit in the number .
Solution:
- Identify the position: The digit is the second digit to the right of the decimal point. \n2. Name the place: The second place to the right is the Hundredths place. \n3. Calculate the value: .
Explanation:
The digit occupies the hundredths position, meaning it represents parts out of equal parts of a whole.
Problem 2:
Convert the fraction into a decimal and write it in expanded form.
Solution:
- Decimal Conversion: (We use in the tenths place because there are no tenths). \n2. Expanded Form (Fractions): . \n3. Expanded Form (Decimals): .
Explanation:
To write the decimal, the whole number goes before the point. Since the fraction is , the must be in the hundredths place, requiring a placeholder zero in the tenths place.