# Lesson 3 Add or Subtract to Solve Story Problems

Let’s solve story problems.

## Warm-up How Many Do You See: Base-ten Diagram

How many do you see? How do you see them?

## Activity 1 Fun at the Zoo

Some students were waiting on the bus to go to the zoo. Then 34 more students got on. Now there are 55 students on the bus. How many students were on the bus at first?

## Activity 2 More Fun at the Zoo

Solve each story problem. Show your thinking.

There were 65 students in the monkey house. 23 left to see the hippos. How many are still in the monkey house?

58 students went to see the bears. 27 students went to see the lions. How many more students went to see the bears than the lions?

Some birds were in cages outside of the bird house. 34 birds were inside the bird house. In all, there were 88 birds. How many were in the cages outside?

## Practice Problem

## Problem 1

There are 34 children in Mai’s classroom. There are 21 children in Noah’s classroom. How many more children are in Mai’s classroom than in Noah’s classroom? Show your thinking using drawings, numbers, or words and write an equation.