1
What do you notice?
What do you notice?
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What do you wonder?
What do you wonder?
Grade 3 Unit 3
Lesson 19: Situations and Equations
CC BY 2021 Illustrative Mathematics®
Grade 3 Unit 3
Lesson 19: Situations and Equations
CC BY 2021 Illustrative Mathematics®
What do you notice?
What do you wonder?
Match each diagram with a situation. Be ready to explain your reasoning.
Situation 1: Mai had 104 beads. She bought two packs of beads and now she has 124 beads. How many beads were in each pack?
Match each equation with a letter for the unknown quantity to a situation in Part 1.
104 + 2 x 10 = n
Kiran is setting up a game of mancala. He has a jar of 104 stones.
From the jar, he takes 3 stones for each of the 6 pits on his side of the board.
Write an equation to represent the situation. Use a letter for the unknown quantity.
Solve the problem. Explain or show your reasoning.
Explain how you know your answer makes sense.
Andre has 196 beads. He uses 48 beads to make a craft. Then he gives 30 beads to a friend. How many beads does Andre have left?
Write an equation with a letter for the unknown quantity to represent this situation.
Solve the problem. Explain or show your reasoning.
Explain your reasoning.
Situation 2: Mai had some beads. She bought 2 more packs of beads and each pack has 10 beads in it. Now she has 124 beads. How many beads did Mai have before?
Explain your reasoning.
Situation 3: Mai had 104 beads. She bought 2 more packs of beads and each pack has 10 beads in it. How many beads does she have now?
Explain your reasoning.
104 + (2 x n) = 124
n + 10 + 10 = 124
