What are Decimals?

Decimals are a way of expressing parts of a whole. They are used to represent numbers that are not whole numbers, such as fractions or parts of a whole unit. Decimals are based on the powers of 10 and are written using a decimal point.

Decimal Notation

Decimals are written using a decimal point to separate the whole number part from the fractional part. For example, the number 3.5 consists of the whole number 3 and the fraction 0.5. The decimal point separates the two parts.

Place Value of Decimals

Each digit in a decimal number has a specific place value based on powers of 10. The digits to the left of the decimal point represent whole numbers, while the digits to the right of the decimal point represent fractions or parts of a whole. The place values to the right of the decimal point are powers of 10 with negative exponents, such as tenths, hundredths, thousandths, and so on.

Comparing and Ordering Decimals

When comparing decimal numbers, you can look at the digits to the left of the decimal point first. If they are the same, you can then compare the digits to the right of the decimal point. When ordering decimals, you can line up the decimal points and compare the digits from left to right.

Operations with Decimals

Decimals can be added, subtracted, multiplied, and divided just like whole numbers. When performing these operations, it's important to line up the decimal points to ensure the correct placement of the decimal point in the result.

Rounding Decimals

Rounding decimals involves identifying the place value to which you want to round and then looking at the digit to the right of that place value. If the digit is 5 or greater, you round up; if it is less than 5, you round down.

Converting Decimals

Decimals can be converted to fractions or percentages. To convert a decimal to a fraction, you can use the place value of the decimal to create the equivalent fraction. To convert a decimal to a percentage, you can multiply the decimal by 100.

◂Math Worksheets and Study Guides First Grade. Odd and Even

Identifying Even and Odd Numbers

The resources above cover the following skills:

Number and Operations (NCTM)

Understand numbers, ways of representing numbers, relationships among numbers, and number systems.

Count with understanding and recognize 'how many' in sets of objects.

Develop a sense of whole numbers and represent and use them in flexible ways, including relating, composing, and decomposing numbers.

Connect number words and numerals to the quantities they represent, using various physical models and representations.

Grade 1 Curriculum Focal Points (NCTM)

Number and Operations: Developing an understanding of whole number relationships, including grouping in tens and ones

Children compare and order whole numbers (at least to 100) to develop an understanding of and solve problems involving the relative sizes of these numbers. They think of whole numbers between 10 and 100 in terms of groups of tens and ones (especially recognizing the numbers 11 to 19 as 1 group of ten and particular numbers of ones). They understand the sequential order of the counting numbers and their relative magnitudes and represent numbers on a number line.

Connections to the Grade 1 Focal Points (NCTM)

Algebra: Through identifying, describing, and applying number patterns and properties in developing strategies for basic facts, children learn about other properties of numbers and operations, such as odd and even (e.g., 'Even numbers of objects can be paired, with none left over'), and 0 as the identity element for addition.

What are Decimals?

Decimal Notation

Place Value of Decimals

Comparing and Ordering Decimals

Operations with Decimals

Rounding Decimals

Converting Decimals

[Decimals] Related Worksheets and Study Guides:

◂Math Worksheets and Study Guides First Grade. Odd and Even

The resources above cover the following skills: