Learn · Illustrative Mathematics K–5 · Grade 2 · Unit 5
Short lessons you can play with. Make hundreds from tens, build and name three-digit numbers, write them in expanded form, and find, compare, and order them, 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 1,000. The blocks are base-ten diagrams: a big square is a hundred, a stick is a ten, and a small square is a one. There’s no adding or subtracting in this unit; that comes in Unit 7.
10 ones make a ten and 10 tens make a hundred, so each digit’s place tells what it’s worth. The same number can be built different ways, like 3 hundreds and 14 tens for 440.
Center Days (Lessons 7 and 13) and Hundreds of Objects (Lesson 14) are optional lessons that work better in class. Practice it all in Dragon Duel, the game for this unit.