In mathematical addition, the higher the base numbers being added, the more frequently students might have to regroup or carry when adding each decimal place together first; however, this concept may be difficult for young students to grasp without a visual representation to help them.

This concept of regrouping can best be explained by demonstrating that each decimal place can only go up to 10, so if the result of adding the two numbers in the same decimal place results in a number greater than 10, the student should write down the number in the ones' decimal place then "carry" the other 1 from the 10 into the tens' decimal place, and if the result of adding both tens' decimal place values is over 10, then that 1 would be "carried" over to the hundreds' decimal place.

While this concept may seem complex, it's best understood through practice. Use the following 3-digit addition with regrouping worksheets to help guide your students or child through learning how to add large numbers together.

### Explore the Concept of Additional Regrouping with These Worksheets

By second grade, students should be able to complete worksheets #1, #2, #3, #4, and #5, which require students to use regrouping to calculate sums of large numbers, though some may still need visual aids like counters or number lines to calculate each decimal point value.

Teachers should encourage students to write on the printed worksheets and remember to "carry the one" each time it occurs by writing a small 1 above the next decimal value then writing the total (minus 10) in the decimal place that was being calculated.

By the time students get to three-digit addition, they typically have already developed a fundamental understanding of the sum of adding most single-digit numbers together, so they should be able to quickly understand how to add even these larger numbers if they just take addition "one column at a time" by adding each decimal place individually and "carrying the one" when the sum is over 10.

### Additional Worksheets and Concepts of 3-Digit Addition

Worksheets #6, #7, #8, #9, and #10 explore questions that produce 4-digit sums and often times require students to regroup multiple times per addition. These can be challenging for beginner mathematicians, so it's best to walk students through the core concepts of three-digit addition thoroughly before challenging them with these more difficult worksheets.

This practice can be expanded infinitely after this point as each decimal place after the three-digit "hundreds' decimal place" operates in exactly the same manner as those before it. By the time students reach the end of the second grade, though, they should be able to add as large of numbers as they want together and even add more than two three-digit numbers to one another by following the same rules.

The students' understanding of these concepts will greatly impact their aptitude in the field of advanced mathematics they will have to study in junior high and high school, so it's important that elementary school teachers ensure their students fully grasp the concept before continuing to multiplication and division lessons.