How to Teach Rounding to the Nearest 10 and 100 in 2nd Grade

As a 2nd grade teacher, I’ve learned that teaching rounding can be a tricky concept for students to grasp at first. However, with the right approach and plenty of hands-on practice, students can become great at this in no time :)

In my classroom, rounding is not just about learning rules... it’s about helping kids understand place value and how numbers work in the real world. Here’s a quick summary of how I’ve taught my students to round numbers to the nearest 10 and 100, with some tips and activities you can try in your own classroom 😊

Place Value is Key

Before diving into rounding, I always review the concept of place value with my students. This is where it all starts. In 2nd grade, we focus on understanding hundreds, tens, and ones, which makes rounding much easier for students to understand.

In one of our lessons, I had students break down the number 345 by its place value: 3 in the hundreds place (300), 4 in the tens place (40), and 5 in the ones place (5). Understanding how each digit contributes to the overall number helps students know exactly what to look for when rounding.

Reinforcement of Rounding Concepts

To make rounding stick, I reinforce the concepts of rounding to the nearest 10 and 100 using a few methods. One of the key practices I incorporate is having my students complete worksheets that focus on rounding 2-digit and 3-digit numbers. My students like the hands-on practice of rounding numbers like 46 and 83 to the nearest 10, and it’s an excellent way to solidify their understanding.

Rounding to the Nearest 10

Once the place value concept is solid, we jump right into rounding to the nearest 10. I tell my students that they’ll look at the ones digit to determine whether to round up or stay the same. If the digit is 5 or greater, we round up. If it’s less than 5, we round down.

For example, with the number 36, the ones digit is 6, so we round up to 40. This step is easy for them to grasp because it’s a simple rule, and they get to practice it on numbers they’re already comfortable with.

Rounding to the Nearest 100

Once the students have grasped rounding to the nearest 10, I introduce rounding to the nearest 100. This is where students get to see how place value plays a bigger role.

For example, with a number like 156, we look at the tens digit (5). Since 5 or greater rounds up, the number rounds to 200. But with a number like 247, the tens digit is 4, so we round down to 200. This concept took a little more time for my students to fully understand, but with practice, they started to see the patterns.

Combining solid place value understanding with plenty of hands-on practice, will help students grasp the concept of rounding much quicker...