Estimation is the process of finding an approximate value for a quantity when the exact value is not known or is impractical to find. It is an important skill in mathematics and everyday life.

There are two main types of estimation:

**Rounding:**Rounding is the process of finding a nearby value that is easier to work with. For example, rounding 347 to the nearest ten gives 350.**Front-End Estimation:**Front-end estimation is a method of estimation where only the first digits of the numbers are used to find the approximate sum or difference. For example, to estimate 347 + 289, you would add 300 + 200 to get 500.

Estimation is used in various real-life situations such as:

- Estimating costs for a project
- Estimating time required for a task
- Estimating the amount of ingredients needed for a recipe
- Estimating distances when traveling

There are several techniques for estimation, including:

**Compatible numbers:**Choosing numbers that are easy to work with and close to the actual values.**Front-end estimation:**Using the first digits of numbers to estimate sums and differences.**Rounding:**Approximating numbers to the nearest ten, hundred, or thousand to simplify calculations.

Here are some practice problems to test your estimation skills:

- Estimate the sum of 456 and 278 using rounding.
- Estimate the difference between 789 and 342 using front-end estimation.
- Estimate the product of 23 and 47 using compatible numbers.

Remember, estimation is a valuable skill that can help you make quick and reasonable approximations in various situations.

Study GuideEstimation Worksheet/Answer key

Estimation Worksheet/Answer key

Estimation Worksheet/Answer key

Estimation Worksheet/Answer key

Estimating to the Nearest Hundreds

Number and Operations (NCTM)

Compute fluently and make reasonable estimates.

Develop and use strategies to estimate the results of whole-number computations and to judge the reasonableness of such results.

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 4 Focal Points (NCTM)

Number and Operations: Building on their work in grade 3, students extend their understanding of place value and ways of representing numbers to 100,000 in various contexts. They use estimation in determining the relative sizes of amounts or distances. Students develop understandings of strategies for multi-digit division by using models that represent division as the inverse of multiplication, as partitioning, or as successive subtraction. By working with decimals, students extend their ability to recognize equivalent fractions. Students' earlier work in grade 3 with models of fractions and multiplication and division facts supports their understanding of techniques for generating equivalent fractions and simplifying fractions.