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Fractions, Decimals, and Percentages - Decimal place value up to thousandths

Grade 5IGCSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

Understanding the Decimal Point: The decimal point separates the whole number part from the fractional part.

Place Value Positions: Digits to the right of the decimal point represent Tenths (1/10), Hundredths (1/100), and Thousandths (1/1000).

Value of Digits: In the number 0.582, '5' is 5 tenths, '8' is 8 hundredths, and '2' is 2 thousandths.

Expanded Form: Writing a decimal as the sum of its parts (e.g., 4.325=4+0.3+0.02+0.0054.325 = 4 + 0.3 + 0.02 + 0.005).

Comparing Decimals: To compare, align the decimal points and compare digits from left to right (tenths, then hundredths, then thousandths).

Rounding: To round to the nearest hundredth, look at the thousandths digit; if it is 5 or more, round up.

📐Formulae

Tenths=110=0.1\text{Tenths} = \frac{1}{10} = 0.1

Hundredths=1100=0.01\text{Hundredths} = \frac{1}{100} = 0.01

Thousandths=11000=0.001\text{Thousandths} = \frac{1}{1000} = 0.001

Decimal to Fraction: 0.abc=abc1000\text{Decimal to Fraction: } 0.abc = \frac{abc}{1000}

💡Examples

Problem 1:

Identify the place value of the digit 7 in the number 12.473.

Solution:

Hundredths

Explanation:

In 12.473, 4 is in the tenths place, 7 is in the hundredths place, and 3 is in the thousandths place.

Problem 2:

Write the decimal 0.045 as a fraction in its simplest form.

Solution:

9200\frac{9}{200}

Explanation:

0.045 has three decimal places, so it is 451000\frac{45}{1000}. Dividing both the numerator and denominator by 5 gives 9200\frac{9}{200}.

Problem 3:

Which number is greater: 0.509 or 0.51?

Solution:

0.51

Explanation:

Compare the digits. Both have 0 wholes and 5 tenths. In the hundredths place, 0.51 has 1, while 0.509 has 0. Since 1 > 0, 0.51 is greater (you can also think of 0.51 as 0.510).

Problem 4:

Round 3.1415 to the nearest thousandth.

Solution:

3.142

Explanation:

The thousandths digit is 1. The digit to its right (ten-thousandths) is 5. Since it is 5 or greater, we increase the thousandths digit by 1.