Addition and subtraction - Add two three-digit numbers not crossing 10 or 100 - Presentation

The lesson plan focuses on the addition of two three-digit numbers without crossing the tens or hundreds boundaries. It emphasizes the importance of aligning numbers correctly in the place value columns for accurate calculation. Students are encouraged to discuss why careful alignment is crucial before moving on to a series of activities designed to practice this skill. The first activity presents a calculation where students must complete the sum by correctly placing hundreds, tens, and ones. They are also invited to visually represent the calculation to enhance their understanding of the concept. The lesson continues with similar exercises, reinforcing the correct placement of digits and the use of column addition to arrive at the sum of three-digit numbers.

Subsequent activities in the lesson plan involve more complex addition problems, still adhering to the rule of not crossing over tens or hundreds. Students are given opportunities to work out sums such as 732 plus 118, 47 plus 521, and 534 plus 12, ensuring they understand the significance of correctly aligning numbers in the place value chart. Additionally, the lesson includes reasoning tasks where students must identify and correct errors in given calculations, such as Tia's miscalculation of 406 plus 353. They learn the importance of using zero as a placeholder in the tens column. The lesson concludes with independent work, where students use base ten blocks for visual representation and solve additional problems, further solidifying their skills in addition without crossing numerical boundaries.