Learn · Illustrative Mathematics K–5 · Grade 3 · Unit 4
Short lessons you can play with. Split things into equal groups, read and write division, find a missing factor, use the multiplication table, break apart rectangles, and multiply and divide larger numbers, then check yourself.
Nine short chapters follow the unit’s lessons in order (the four-operations lessons, 17 and 21, share the last chapter). 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. Progress is saved on this device.
Multiplication and division facts stay within 10 × 10, and division never has a remainder. Larger products are a one-digit number times a multiple of ten, or times a teen or two-digit number with a product within 100. Larger divisions have a one-digit divisor and stay within 100.
Divide: split a number into equal groups. Quotient: the answer to a division. Factor: a number being multiplied; division finds a missing factor, so 28 ÷ 4 = ? asks 4 × ? = 28. Fact family: the multiplication and division facts that go with one array, like 3 × 5, 5 × 3, 15 ÷ 3, and 15 ÷ 5. Multiple of ten: 10, 20, 30, and so on. Area diagram: a rectangle with its sides split, not drawn in squares.
School Community Garden (Lesson 22) is an optional lesson. Practice it all in Toy Workshop, the game for this unit.