Learn · Illustrative Mathematics K–5 · Grade 2 · Unit 4
Short lessons you can play with. Find numbers on a number line, compare and estimate, then add and subtract with jumps, then check yourself. Tap Read to me to hear any step read aloud.
Five short chapters follow the unit’s lessons in order. Each step shows one idea with something to tap or move, then a quick check. A wrong answer names the likely mistake and gives one more try.
The Read to me buttons read each step and quick check aloud with the device’s built-in voice, for students still learning to read. Progress is saved on this device.
All numbers are within 100. Jumps stop at a ten on the way, or go by tens and then ones, so each problem needs at most one new or broken ten.
On a number line, a number is a length from 0. Adding is a jump to the right, subtracting is a jump to the left, and the difference between two numbers is the distance between them.
Center Days (Lessons 6 and 14) and Riddles (Lesson 15) are optional lessons that work better in class. There’s no practice game for this unit yet.