Estimations

Estimation is the technique of estimating or rounding off values to prevent laborious calculations. “Rounding off” is the process of simplifying the complexity of a number by maintaining its value while moving it closer to the next number.

It is carried out for both whole numbers and decimals in various place values, such as hundreds, tens, tenths, etc. The numbers are rounded off to keep the major figures.

Numerous businesses, including news, social media, weather forecasting, stock markets, etc., use estimation to solve calculations quickly and save time.

In this teaching guide, we will cover the following estimations :

• Estimations of whole numbers
• Estimations of decimals
• Estimations in four operations (addition, subtraction, multiplication, and division)

## Rounding off for whole numbers

1. Rounding Off to the Nearest 10 :
• Round the number down if the units place has 1, 2, 3, or 4.
• Round up the number if the units place has a 5, 6, 7, 8, or 9.
• Simply take into consideration the last two digits of any number to round it off closer to the tens. Digits in the tens place and units place.
• For example, Round off 45776 to its nearest tens.
• Here, the last two digits of 45776 are ⟶ 7 and 6.
• At the units place, the number is 6. So, we need to round up the number. Replace the number 76 with 80. The number 76 is nearest to 80 than 70.
1. Rounding Off to the Nearest 100 :
• Round the number down if the tens place has 0, 1, 2, 3, or 4.
• Round up the number if the tens place has a 5, 6, 7, 8, or 9 .
• Simply take into consideration any number’s last three digits, the hundreds place, tens place, and units place digits, in order to round it off to the closest hundreds.
• For example, Round off 68526 to the nearest hundred.
• Here, the last three digits of 68526 are ⟶ 526.
• Tens place has number 2. So, we need to round down the number.  Replace the number 526 with 500. Before 526 the nearest hundred number is 500.
1. Rounding Off to the Nearest 1000 :
• Round the number down if the hundreds place has 0, 1, 2, 3, or 4.
• Round up the number if the hundreds place has a 5, 6, 7, 8, or 9.
• Simply take into consideration any number’s last four digits, the thousands place, hundreds place, tens place, and units place digits, in order to round it off to the closest hundreds.
• For example, Round off 52936 to its nearest thousand.
• Here, the last four digits are 52936 ⟶ 2936.
• Hundreds place has number 9. So, we need to round up the number. Replace the number 2936 by 3000. After 2936 the nearest thousand number is 3000.

## Rounding off for decimal numbers

he guidelines for rounding off decimal numbers are as follows:

• To find it, look to the right of the rounding digit.
• If the right-hand numbers are less than five, consider them to be equal to zero.
• If the right-hand digits are larger than or equal to 5, add 1 to that digit, and the remaining digits should be treated as zero.

## Estimations in four operations (addition, subtraction, multiplication and division)

• To estimate any of the four operations, we first need to round off the numbers to be operated.
• Numbers to be operated on are rounded off, following the basic rule of rounding up or down the numbers.
• The operation is carried out on the estimated numbers, and the final answer is obtained.

Story

Ignite kids’ curiosity with engaging stories for role play and skits, making the learning of this concept an exciting and effective experience. Teaching  estimations through stories from Uncle Math School by Fun2Do Labs :

Text Of The Stories :

Posters

Teaching types of lines with kid-friendly, clear, and easy-to-understand posters from Uncle Math School by Fun2Do Labs

Activities

Learning estimations can be made enjoyable by incorporating interactive games and activities.

### Hands Up!

In this activity, children have a lot of fun and enjoy learning while playing. This one is a simple physical activity that further reinforces the concept of rounding off.

1. Instruct children to raise their hands up on hearing any number if they feel the number would be rounded up.
2. Instruct children to put their heads down on hearing any number if they feel the number would be rounded down.
3. So, the game begins as soon as instructions are clear to children. Announce the number and get set, go!!!

Worksheets

Help your kids practise estimations with interesting and engaging fun worksheets and solutions from Uncle Math by Fun2Do Labs.