Fractions and Decimals
Key Concepts
Fractions and decimals are ways to represent parts of a whole. Fractions are written as one number over another, while decimals are written with a decimal point.
Fractions
A fraction represents a part of a whole. It consists of two numbers: the numerator (the top number) and the denominator (the bottom number). The numerator tells us how many parts we have, and the denominator tells us how many equal parts the whole is divided into.
Examples
Let's look at the fraction 3/4:
- The numerator is 3, which means we have 3 parts.
- The denominator is 4, which means the whole is divided into 4 equal parts.
Another example is 2/5:
- The numerator is 2, which means we have 2 parts.
- The denominator is 5, which means the whole is divided into 5 equal parts.
Analogies
Think of fractions like slices of a pizza. If you have a pizza divided into 8 slices and you eat 3 slices, you have eaten 3/8 of the pizza.
Decimals
Decimals are another way to represent parts of a whole. They use a decimal point to separate the whole number from the fractional part. The digits to the right of the decimal point represent tenths, hundredths, thousandths, and so on.
Examples
Let's look at the decimal 0.75:
- The number 0 is the whole number part.
- The number 75 represents 75 hundredths, which is the same as 3/4.
Another example is 0.4:
- The number 0 is the whole number part.
- The number 4 represents 4 tenths, which is the same as 2/5.
Analogies
Think of decimals like money. If you have $0.75, it means you have 75 cents out of a dollar, which is the same as having 3 quarters.
Converting Between Fractions and Decimals
You can convert fractions to decimals by dividing the numerator by the denominator. For example, to convert 3/4 to a decimal:
- 3 รท 4 = 0.75
To convert a decimal to a fraction, write the decimal as a fraction with the appropriate denominator. For example, to convert 0.75 to a fraction:
- 0.75 = 75/100 = 3/4
Practical Application
Understanding fractions and decimals helps in many real-world situations, such as measuring ingredients for cooking, understanding money, and interpreting data. For example, if a recipe calls for 3/4 cup of sugar, you can measure it accurately using a measuring cup marked in fractions.