Students will be able to use two different strategies to subtract three-digit numbers.
The adjustment to the whole group lesson is a modification to differentiate for children who are English learners.
Write the following problem on the board: 365 – 174.
Distribute the whiteboards and ask students to solve the problem using a strategy of their choice. Then, ask students to turn to their elbow partner to compare strategies and answers.
Choose students who used different strategies to share their steps to solve the problem.
Solve the problem on the board using expanded form subtraction and highlight that you have to regroup. Define regrouping as changing groups of ones, tens, or hundreds into another value (e.g., changing 1 ten to 10 ones).
Explain that they'll learn two strategies for solving subtraction problems to help them check their answers and better understand subtraction processes.
Introduce and explain key vocabulary such as "strategy," "subtraction," "expanded notation," and "regrouping." Provide student-friendly definitions in English (L2) and students' home language (L1). Show images and examples when appropriate.
Give students sentence stems/frames to help them share and compare strategies:
"I solved the subtraction problem with the ________ strategy."
"I used the ________ strategy because..."
"My strategy is ________ while your strategy is ________."
"One similarity in our two strategies is that they both..."