### Lesson plan

# Adding it All Up

#### Learning Objectives

Students will be able to add a one-digit number to a two-digit number with regrouping.

The adjustment to the whole group lesson is a modification to differentiate for children who are English learners.

#### Introduction

*(5 minutes)*

- Ask two volunteers to come to the front of the classroom.
- Give one student a two-digit number. Give the other student a one digit number. Instruct the students to use base-ten blocks to add their numbers together.
- Have the rest of the class use base-ten blocks to model the addition problem at their desks.
- Ask students to share some information. Great questions include:
*What is the sum of your addition problem? What strategies did you use to find the sum?* - Tell students that today we're going to add two-digit numbers.

#### Explicit Instruction/Teacher modeling

*(10 minutes)*

- Write the following problem on the board:
*Tess raked 18 leaves on Monday. She raked 7 leaves on Friday. How many leaves did she rake in all?* - Ask students to read the problem aloud with you.
- Guide students in using base-ten blocks to show 7 and 18.
- Explain to students that when adding a two-digit number, add the ones first. Then add the tens.
- Ask students how many ones there are total.
- Show students how to make a group of 10 ones, by connecting ten cubes together. Instruct them to trade these ten blocks for 1 ten.
- Discuss the term regrouping. Define
**Regrouping**As the process of changing groups of ones into tens to make adding and subtracting easier. - Once you've made a ten from the ones, count the number of ones that are leftover.
- Ask students how many tens and ones are there now.
- Have students write a number sentence to solve the problem.
- Repeat steps using two different numbers.

#### Guided practise

*(10 minutes)*

- Write the following problems on the board vertically, so place values are aligned:
- 27 + 7 , 33 + 8 , 19 + 3 , 24 + 7

- Give each student an index card or half-sheet of paper.
- Work through the steps together to complete the problems.
- Remind students that a number line can also be used to help add.

#### Independent working time

*(15 minutes)*

- Have students complete the problems on the Addition worksheet independently.

#### Differentiation

**Enrichment:**Challenge advanced students to complete the problems without manipulatives.

**Support:**Encourage struggling students to continue using manipulatives to add or draw a picture to demonstrate how they can regroup.

#### Assessment

*(5 minutes)*

- Tell students to turn their index card or half-sheet over, to complete a problem on the back.
- Ask them to find the sum for
**17 + 6**, and draw or write to explain how they found it.

#### Review and closing

*(5 minutes)*

- Review effective strategies for adding one-digit and two-digit numbers, including the definition for regrouping.