Adding Three Digit Numbers Lesson Plan for 3rd Grade Students

Topic:Adding three digit numbers

Objectives & Outcomes

• Students will be able to add three digit numbers with regrouping and without regrouping.

Materials

• Pencils
• Paper
• Calculator (optional)

Warm-up

• Review the concept of carrying and borrowing using simple addition problems with one digit numbers such as 5+6 and 8+3. Ask the students to explain the concept of carrying and borrowing.

Direct Instruction

• Introduce the concept of carrying three digit numbers. Show an example of adding three digit numbers using the traditional method of carrying and borrowing. Ask the students to explain how the concept of carrying works in this case.
• Next, introduce the concept of borrowing. Show an example of adding three digit numbers using the traditional method of carrying and borrowing, but this time with the concept of borrowing. Ask the students to explain how the concept of borrowing works in this case.
• Finally, demonstrate how to use the abacus to add three digit numbers. Show an example of adding two three digit numbers using the abacus. Ask the students to observe and explain how the abacus works.

Guided Practice

• Provide the students with two three digit numbers to add using the abacus. One of the numbers should have at least one digit in common with the other number. Have the students work in pairs to use the abacus to add the two numbers.
• As the students work, circulate around the room and provide assistance as needed.

Independent Practice

• Provide each student with a sheet of paper and a pencil. On the sheet of paper, have the students draw an abacus and use the pencil to add three digit numbers.
• Encourage the students to check their answers with a calculator, and to show their work on the abacus.

Closure

• Review the steps for adding three digit numbers with carrying: add the ones digits, add the tens digits, and if there is a remainder, carry the digit over to the next column.
• Ask the students to share their abacus drawings and explain their strategies for adding the numbers.

Assessment

• Observe the students during the independent practice activity and provide feedback on their use of the abacus and their decision-making when carrying numbers.
• Use the completed abaci as a form of assessment, evaluating the students' ability to correctly add three digit numbers with carrying.