Practical Arithmetic

Rounding and Estimating Number

Sometimes it is not necessary to use exact number, an approximate can also be used in lieu of the exact number. Such approximation can be obtained only through rounding numbers, and all number can be rounded to specific place values.

Estimating by Rounding

In this module, students will learn how to estimate a sum or difference by first rounding each number to the nearest ten, nearest hundred... and so on.

Estimating by Clustering

This module discusses how to estimate by clustering, and students should be able estimate the result of adding more than two numbers when clustering occurs.

Front-End Estimation

Through this module will be able to learn how to estimate a sum by front end estimation, and be able to use it and recognize it.

Estimating by Using Compatible Numbers

In this module student will learn, the meaning of compatible numbers. And when to use compatible numbers to estimate the value of an expression.