Videos and solutions to help Grade 3 students learn how to solve word problems in varied contexts using a letter to represent the unknown.

Common Core Standards: 3.OA.8

Related Topics:

Lesson Plans and Worksheets for Grade 3, Lesson Plans and Worksheets for all Grades, More Lessons for Grade 3, Common Core For Grade 3

New York State Common Core Math Module 7, Grade 3, Lesson 1, Lesson 2

Lesson 1 Concept Development

Lena’s family visits Little Tree Apple Orchard. Use the RDW process to solve the problems about Lena’s visit to the orchard. Use a letter to represent the unknown in each problem.

The sign below shows information about hayrides at the orchard. Lena’s family buys 2 adult tickets and 2 child tickets for the hayride. How much does it cost Lena’s family to go on the hayride?

Adult Ticket ............................ $7

Child Ticket ............................ $4

Max’s family takes the train to visit the city zoo. Use the RDW process to solve the problems about Max’s trip to the zoo. Use a letter to represent the unknown in each problem.

1. The sign below shows information about the train schedule into the city.

a. Max’s family buys 2 adult tickets and 3 child tickets. How much does it cost for Max’s family to take the train into the city?

b. Max’s father pays for the tickets with $10 bills. He receives $6 in change. How many $10 bills does Max’s father use to pay for the train tickets?

c. Max’s family wants to take the fourth train of the day. It’s 6:38 a.m. now. How many minutes do they have to wait for the fourth train?

2. At the city zoo, they see 17 young bats and 19 adult bats. The bats are placed equally into 4 areas. How many bats are in each area?

3. Max’s father gives the cashier $20 to pay for 6 water bottles. The cashier gives him $8 in change. How much does each water bottle cost?

4. The zoo has 112 species of reptiles and amphibians in their exhibits. There are 72 species of reptiles and the rest are amphibians. How many more species of reptiles are there than amphibians in the exhibits?

Use the RDW process to solve. Use a letter to represent the unknown in each problem.

1. A box containing 3 small bags of flour weighs 950 grams. Each bag of flour weighs 300 grams. How much does the empty box weigh?

2. Mr. Cullen needs 91 carpet squares. He has 49 carpet squares. If the squares are sold in boxes of 6, how many more boxes of carpet squares does Mr. Cullen need to buy?

3. Erica makes a banner using 4 sheets of paper. Each paper measures 9 inches by 10 inches. What is the total area of Erica's banner?

4. Monica scored 32 points for her team at the Science Bowl. She got 5 four-point questions correct, and the rest of her points came from answering three-point questions. How many three-point questions did she get correct?

5. Kim's black kitten weighs 175 grams. Her gray kitten weighs 43 grams less than the black kitten. What is the total weight of the two kittens?

Use the RDW process to solve. Use a letter to represent the unknown in each problem.

1. The total amount of rain that fell in New York City in two years was 282 centimeters. In the first year, 185 centimeters of rain fell. How many more centimeters of rain fell in the first year than in the second year?

2. Cassias and Javier’s combined height is 267 centimeters. Cassias is 128 centimeters tall. How much taller is Javier than Cassias?

Rotate to landscape screen format on a mobile phone or small tablet to use the **Mathway** widget, a free math problem solver that **answers your questions with step-by-step explanations**.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.