Learn · Illustrative Mathematics K–5 · Grade 4 · Unit 6
Short lessons you can play with. Grow patterns, multiply big numbers with area diagrams and the standard algorithm, share base-ten blocks to divide, and decide what to do with a remainder, then check yourself.
Eight 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. Progress is saved on this device.
Multiplying goes up to 4 digits by 1 digit and 2 digits by 2 digits, first on area diagrams split by place value, then as partial products, then with the standard algorithm for a one-digit number. Dividing goes up to 4 digits by 1 digit, with base-ten blocks and partial quotients. Remainders come only with a story that says what to do with them.
Partial products: the products of each place, added to make the whole product. Standard algorithm: multiplying one place at a time, carrying to the next place. Partial quotients: dividing in easy chunks and adding them up. Remainder: what’s left over after making equal groups.
Paper Flower Decorations (Lesson 25) is an optional lesson. Practice it all in City Builders, the game for this unit.