Adding with Regrouping Background Information for Teachers and Parents
This page contains information to support educators and families in teaching K-3 students about adding with regrouping. The information is designed to complement the BrainPOP Jr. movie Adding with Regrouping. It explains the type of content covered in the movie, provides ideas for how teachers and parents can develop related understandings, and suggests how other BrainPOP Jr. resources can be used to scaffold and extend student learning.
Adding with regrouping can be a tricky concept for some children, so we recommend solving different number sentences together using number lines, hundred charts, and hands-on manipulatives, such as base-ten blocks. We also recommend reviewing math strategies that children can use to help solve number sentences that require regrouping. You may wish to review the Doubles and Basic Addition movies to brush up on a few strategies. This movie will cover addition with regrouping involving two-digit and one-digit numbers.
Show children the number sentence 8 + 6. Use a number line or hundred chart to solve together. Then use base-ten cubes to show the numbers 8 and 6. Remind children that a tens rod is equal to 10 cubes. They can group 10 cubes together to form 1 tens rod. That means there will be 4 cubes left over. What number does that show? Encourage children to count the ones and the tens to make the number instead of counting each cube one by one. Show that 8 + 6 = 14. Explain to children that when they regroup, they gather ten ones to make one group of ten. Repeat the activity again to solve 15 + 9 and 39 + 6. Use base-ten blocks and have children combine the cubes into rods to find each sum.
After children are familiar with regrouping using manipulatives, invite them to solve number sentences using pencil and paper. Show the number sentence 17+ 8 in vertical form. Remind children that when they add numbers with more than one digit, they add the ones column first, then add the tens column. What is 7 + 8? Some children may remember that since 8 + 8 = 16, 7 + 8 will be one less than 16, or 15. Teach them how to write 5 in the total and then carry the 1 over to the tens. Then add the tens column: 1 + 1 = 2. Therefore, 17 + 8 = 25. Solve more number sentences together, such as 56 + 9 and 87 + 4.
Present different word problems to children and have them make up their own stories for other people to solve. Have children verbally explain how they add and regroup while solving number sentences using base-ten blocks or with pencil and paper. This will help them visualize and explain the process to themselves and gives you an opportunity to guide their thinking process if they run into errors. Encourage children to not give up or get too frustrated. Regrouping can be challenging but becomes much easier with time and practice!