Let’s start building numbers! Just as building skyscrapers is a visual representation of mathematics, students will use the visual representation of base-ten blocks to add—or build—onto a two-digit number.
Build up your students’ addition skills using base-ten blocks. In this lesson plan, Let’s Build It! Two-Digit Addition, first graders will use visual representations to help them add multiples of 10 to two-digit numbers. It’s a great way to practice counting by tens and opens up a discussion about place value and two-digit numbers. By using a mix of learning tools, from whiteboards to base-ten blocks, this lesson uses several different teaching techniques to reinforce math concepts.
Students will be able to add two-digit numbers using both actual and written base-ten blocks.
The adjustment to the whole group lesson is a modification to differentiate for children who are English learners.
Practice counting by tens as a class. As you count, hold up the base-ten rods so that, at the end, you will be holding 10 rods to equal 100.
Show on the board how adding 10 over and over is counting up and building bigger numbers.
Call on students quickly and have them solve problems in which they add 10 every time (50 + 10, 30 + 10, 10 + 10).
Say, “Base-ten blocks help us have a visual of what we are adding, especially when we are adding larger two-digit numbers.”
Ask students how many fingers they have, and count 10 fingers together chorally. Next, have 10 students flash 10 fingers as you count together by tens to 100.
Display a hundreds chart as a visual reference as students solve problems of 10 more.