Whole Numbers
Whole numbers are the numbers 0, 1, 2, 3, 4, 5, and so on. They are the numbers used for counting and are also called non-negative integers. Whole numbers do not include any fractions or decimals, and they do not have any decimal or fractional parts.
In set notation, we can represent whole numbers as {0, 1, 2, 3, 4, ...}. This set starts at 0 and continues infinitely in the positive direction.
Whole numbers are used in various mathematical operations such as addition, subtraction, multiplication, and division. They are fundamental to understanding the number system and are the building blocks for more complex mathematical concepts.
.◂Math Worksheets and Study Guides Third Grade. Double Digit Subtraction
Study Guide
Double Digit Subtraction 
Worksheet/Answer key
Double Digit Subtraction Worksheet/Answer key
Double Digit Subtraction Worksheet/Answer key
Double Digit Subtraction Worksheet/Answer key
Double-Digit Subtraction
Worksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyThe resources above cover the following skills:
Number and Operations (NCTM)
Compute fluently and make reasonable estimates.
Develop fluency in adding, subtracting, multiplying, and dividing whole numbers.
Select appropriate methods and tools for computing with whole numbers from among mental computation, estimation, calculators, and paper and pencil according to the context and nature of the computation and use the selected method or tools.
Algebra (NCTM)
Use mathematical models to represent and understand quantitative relationships.
Model problem situations with objects and use representations such as graphs, tables, and equations to draw conclusions.
Connections to the Grade 3 Focal Points (NCTM)
Number and Operations: Building on their work in grade 2, students extend their understanding of place value to numbers up to 10,000 in various contexts. Students also apply this understanding to the task of representing numbers in different equivalent forms (e.g., expanded notation). They develop their understanding of numbers by building their facility with mental computation (addition and subtraction in special cases, such as 2,500 + 6,000 and 9,000 - 5,000), by using computational estimation, and by performing paper-and-pencil computations.