Learn · Illustrative Mathematics K–5 · Grade 3 · Unit 1
Short lessons you can play with. Read picture graphs and bar graphs where each picture or line counts for more than 1, then see multiplication as equal groups and arrays, write expressions and equations, and find unknown numbers, 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.
Graphs use a scale of 2, 5, or 10, and totals stay within 100. Multiplication uses factors up to 10 and products up to 100. As in class, 4 × 3 means 4 groups of 3: the first factor is the number of groups.
Scale: how much each picture or each line on a graph stands for. Equal groups: groups with the same number in each. Factor: a number being multiplied. Product: the answer to a multiplication. Array: things arranged in equal rows and columns. Commutative property: factors can be multiplied in any order, so 3 × 5 = 5 × 3.
Game Night Seating Plan (Lesson 21) is an optional lesson. Practice it all in Orchard Market, the game for this unit.