Tennis Ball Troubles: Adding and Subtracting Within 100!

Math Grades 1st Grade 3:32 Video
Print Lesson Plan Watch Video

Lesson Description

Join Mrs. Grange's class as we learn how to solve word problems by adding and subtracting tennis balls that are lost and found! We'll use regrouping to help us subtract and figure out how many balls are left.

Video Resource

Losing tennis balls | Addition and subtraction within 100 | Early Math | Khan Academy

Khan Academy

Duration: 3:32
Watch on YouTube

Key Concepts

  • Addition and subtraction within 100
  • Solving word problems
  • Regrouping (borrowing) in subtraction

Learning Objectives

  • Students will be able to solve word problems involving addition and subtraction within 100.
  • Students will be able to identify whether a problem requires addition or subtraction based on the context of the word problem.
  • Students will be able to use regrouping (borrowing) when subtracting two-digit numbers.

Educator Instructions

  • Introduction (5 mins)
    Begin by asking students about times they have lost something (e.g., a toy, a pencil). Discuss how losing something makes the number of items they have smaller. Introduce the idea that we'll be solving a problem about losing tennis balls using math.
  • Video Viewing (7 mins)
    Play the Khan Academy video "Losing tennis balls | Addition and subtraction within 100 | Early Math | Khan Academy." Encourage students to pay attention to how the narrator sets up the problem and solves it.
  • Guided Practice (10 mins)
    Work through a similar word problem with the class, modeling each step. For example: "Sarah has 32 stickers. She gives 15 stickers to her friend. How many stickers does Sarah have left?" Emphasize identifying key information, determining whether to add or subtract, and using regrouping if necessary.
  • Independent Practice (10 mins)
    Provide students with 2-3 word problems to solve on their own. Encourage them to draw pictures or use manipulatives (e.g., blocks, counters) to help them solve the problems.
  • Wrap-up (3 mins)
    Review the key concepts and strategies used in the lesson. Ask students to share their favorite strategy for solving word problems.

Interactive Exercises

  • Tennis Ball Toss
    Divide the class into teams. Create a series of addition and subtraction word problems related to tennis balls (or other familiar objects). Teams take turns answering problems and 'tossing' a (soft) ball into a bucket for each correct answer.
  • Drawing the Problem
    Provide students with word problems and ask them to draw a picture to represent the problem. This helps them visualize the situation and determine the correct operation.

Discussion Questions

  • How do you know if a word problem is asking you to add or subtract?
  • What does it mean to regroup when subtracting?
  • Can you think of a time when you used addition or subtraction in real life?

Skills Developed

  • Problem-solving
  • Critical thinking
  • Addition and subtraction fluency

Multiple Choice Questions

Question 1:

Tom has 25 toy cars. He gives 10 cars to his friend. How many cars does Tom have left?

Correct Answer: 15

Question 2:

Lisa has 12 balloons. Sam gives her 5 more balloons. How many balloons does Lisa have in all?

Correct Answer: 17

Question 3:

There are 30 birds in a tree. 20 birds fly away. How many birds are left in the tree?

Correct Answer: 10

Question 4:

A baker made 42 cookies. He sold 20 cookies. How many cookies are left?

Correct Answer: 22

Question 5:

Sara has 15 stickers. Ben has 10 stickers. How many stickers do they have together?

Correct Answer: 25

Question 6:

A farmer planted 50 seeds. 30 seeds grew into plants. How many seeds did NOT grow?

Correct Answer: 20

Question 7:

There are 28 students in a class. 8 students are absent. How many students are present?

Correct Answer: 20

Question 8:

I have 64 crayons. My little brother broke 4 crayons. How many crayons do I have now?

Correct Answer: 60

Question 9:

A pet store has 33 fish. They sell 3 fish. How many fish are left?

Correct Answer: 30

Question 10:

Anna had 17 apples. She ate 7 apples. How many apples does Anna have left?

Correct Answer: 10

Fill in the Blank Questions

Question 1:

Lily has 35 flowers. She gives 5 flowers to her mom. Lily has _____ flowers left.

Correct Answer: 30

Question 2:

There are 14 kids playing. 6 more kids join. Now there are _____ kids playing.

Correct Answer: 20

Question 3:

I had 40 marbles. I lost 10 marbles. Now I have _____ marbles.

Correct Answer: 30

Question 4:

A farmer had 22 cows. He bought 8 more cows. Now he has _____ cows.

Correct Answer: 30

Question 5:

Kim has 56 beads. She uses 6 beads to make a bracelet. Kim has _____ beads left.

Correct Answer: 50

Question 6:

Ben has 15 books. He reads 5 books. He has _____ books left to read.

Correct Answer: 10

Question 7:

We had 33 cupcakes. We ate 3 cupcakes. Now there are _____ cupcakes.

Correct Answer: 30

Question 8:

A class had 27 pencils. 7 pencils broke. Now there are _____ pencils left.

Correct Answer: 20

Question 9:

I have 88 cents. I spend 8 cents on candy. Now I have _____ cents.

Correct Answer: 80

Question 10:

A box has 44 markers. We take out 4 markers. There are _____ markers in the box now.

Correct Answer: 40

Educational Standards

CCSS.Math.Content.1.OA.A.1:Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem. CCSS.Math.Content.1.NBT.C.4:Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten. CCSS.Math.Content.1.OA.D.8:Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = _ - 3, 6 + 6 = _.

Teaching Materials

Download ready-to-use materials for this lesson:

Student Worksheet Classroom Slides Assessment Quiz Export to Google Docs
Add to Google Classroom

User Actions

Sign in to save this lesson plan to your favorites.

Sign In

Share This Lesson

Related Lesson Plans