Addition & Subtraction – Developing Whole Number Operations

- Grade Level: First
- Standard: Work with addition and subtraction equations –
**1)**Add and subtract within 20,**2)**Represent and solve problems involving addition and subtraction,**3)**Understand and apply properties of operations and the relationship between addition and subtraction - [Prekindergarten through Grade 2] All students should:
**1)**Understand various meanings of addition and subtraction of whole number and the relationship between the two operations,**2)**Understand the effects of adding and subtracting whole numbers - Activities Plan:

- Introduction/Group Lesson: Color Wheel Math – (Grab a blue, yellow, and green crayon. Speak about mixing colors with students (“When you take blue and add yellow, you end up with green”). You are already beginning to teach your students about addition; two small parts [blue and yellow] to get a whole [green]. Then switch up your color addition, teaching them about the commutative property where in addition yellow + blue = green, and blue + yellow = green. Now start with green and say you are taking away [subtraction] all of the yellow, ending up with blue.)
- Basic Knowledge: Open with a Know/Want to Know/Learned Chart. Follow with “Act It Out!” – (Ask for volunteers [approximately 10] to come up to the front of the classroom. The remaining students will be responsible for writing down appropriate numbers and signs. Have 4 students stand in front, and add 6 more for example, asking the students to come up with a total. Here you can speak about the meaning and importance of an addition/subtraction sign and when to use an equal sign. Also, you can point out the importance of placement [5 + 4 = 9 and 4 + 5 = 9, however 5 – 4 = 1 and 4 – 5 = -1)
- Self-Exploration: Unifix Cubes & Math Flowers – (Allow students to free play and explore on their own using the Unifex cubes. Write out equations and provide word problems for students to solve. Use self-correcting math flowers for extra guidance). Group Lesson: I Can Write an Equation! – (With students, create a chart showing the important signs and rules for addition and subtraction [addend/minuend/subtrahend, plus sign/minus sign, equal sign, sum/difference]. Add examples and place on the wall where children can easily see the chart for reference.
- Game: Tic-Tac-Toe Addition & Subtraction – (Provide students with tic-tac-toe boards filled with a variety of addition and subtraction problems. Have them work in pairs to see who can successfully answer each problem.)
- Working with the Number Line – (Create a large number line on the white board and have students use magnets to add and subtract equations.)
- Creating Equations – (“I started with four markers [show four markers] and then Mrs. Cook gave me 5 more markers [show five more markers]. The students will need to write down 4 + 5 on dry erase boards and solve. After some practice, see if students can write equations and solve without modeling the problems out for them.)
- Building Fact Families – (Using clothes pins and popsicle sticks, have children build addition/subtraction facts and fact families. This will allow students to use their fine motor skills while working with academic tasks. After students have had time to build their own equations, provide them with fact family bags and have them determine what fact family they can build using the materials. For example; 5, 12, and 7: 5 + 7 = 12, 7 + 5 = 12, 12 -7 = 5, 12 – 5 = 7)
- Game: Cover Up! – (Provide students with a Cover Up game board, 2 dice, and unifex cubes. The goal is to fill in each number on your side of the board [1-12] by rolling the dice and adding the two numbers. The first one to completely fill their side wins!)
- Making Spiders – (Start by giving each student a large black oval and have them come up with eight equations that equal eight (12 – 4 = 8, 5 + 3 = 8, etc.). Have students write out their equations with white crayon on long, creepy spider legs. After students have glued the legs onto their spiders, allow them to make a face for the spider and display the artwork on the Math Wall!)
- Linking Cubes Addition & Subtraction – (Single or multiplayer game. Students use linking cubes, dice, and a spinner to create equations using the cubes and pictures.) Complete unit by reviewing Know/What to Know/Learned chart. Have students help to finish the “Learned” section.