As math teachers, it is important to equip our students with the tools they need to make quick and accurate estimations. One of these tools is the ability to estimate and compare sums and differences. By learning how to do this efficiently, students will be better equipped to make quick mental calculations both inside and outside of the classroom.

Here are some activities that can help your students develop these skills:

1. The Guessing Game:

Begin by showing your students several sets of two-digit numbers, such as 36 and 48 or 57 and 74. Then, ask them to guess the sum of each set without using paper or a calculator. After they have made their guesses, have them use mental math to add the numbers to see how close their estimates were. This activity will help students become more familiar with different two-digit numbers and the relationship between them.

2. Rounding Up:

Have students round the numbers in a sum or difference to the nearest ten, hundred, or thousand, depending on their level. Then, ask them to estimate the answer by adding or subtracting the rounded numbers. This activity will teach students how to quickly round numbers and estimate sums and differences with greater ease.

3. Practice with Real-Life Problems:

Use real-life problems to help students practice estimating. For example, ask them to estimate the total cost of several items before they go shopping. This exercise will help them hone in on their estimation skills, and it can be a fun way to test their abilities in a real-life context.

4. Telephone Math:

A great way to help students practice estimating and comparing sums and differences is to play telephone math. To play, students should sit in a circle and one student (the teacher) will start by whispering a math problem to the person beside them. For example, the teacher might say “67+98.” The next student must then estimate the answer and whisper it to the student beside them. The process continues until the final student in the circle offers their estimate. The teacher can then reveal the actual answer. This game will help students practice estimating in a fun and engaging way.

5. Estimation Challenges:

Another effective way to help students develop their estimation skills is to have estimation challenges. Create a set of problems for your students to solve, such as adding two-digit numbers or subtracting three-digit numbers. Give them a set amount of time to complete the problems and then review the answers together. This activity will help students work faster and become more accurate in their estimation skills.

In conclusion, these activities will not only help your students improve their math skills but also enhance their confidence in making quick mental calculations. By developing their estimation skills, they will be able to solve problems with greater ease and will have a deeper understanding of the relationship between numbers.