ALEX Resources

   View Standards     Standard(s): [MA2019] (1) 6 :

6. Add and subtract within 20.

a. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by counting on.

b. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by making ten.

c. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by decomposing a number leading to a ten.

Example: 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9

d. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by using the relationship between addition and subtraction.

Example: Knowing that 8 + 4 = 12, one knows 12 - 8 = 4.

e. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by creating equivalent but easier or known sums.

Example: adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13

[MA2019] (1) 8 :

8. Solve for the unknown whole number in various positions in an addition or subtraction equation, relating three whole numbers that would make it true.

Example: determining the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, and 6 + 6 = ?

[MA2019] (1) 13 :

13. Add within 100, using concrete models or drawings and strategies based on place value.

a. Add a two-digit number and a one-digit number.

b. Add a two-digit number and a multiple of 10.

c. Demonstrate that in adding two-digit numbers, tens are added to tens, ones are added to ones, and sometimes it is necessary to compose a ten.

d. Relate the strategy for adding a two-digit number and a one-digit number to a written method and explain the reasoning used.

Students will throw addition problems or answers (on paper) across the classroom and find the matching problem or answer! Students will use mental math to compute the matching answer. Students will quietly walk around the classroom to find the person with the matching paper. Let’s throw math around!

This is a College- and Career-Ready Standards showcase lesson plan.

   View Standards     Standard(s): [MA2019] (1) 3 :

3. Apply properties of operations as strategies to add and subtract.

Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known (commutative property of addition).
To add 2 + 6 + 4, the second and third numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12 (associative property of addition).
When adding 0 to a number, the result is the same number (identity property of zero for addition).

[MA2019] (1) 4 :

4. Explain subtraction as an unknown-addend problem.

Example: subtracting 10 - 8 by finding the number that makes 10 when added to 8

[MA2019] (1) 5 :

5. Relate counting to addition and subtraction.

Example: counting on 2 to add 2

[MA2019] (1) 8 :

8. Solve for the unknown whole number in various positions in an addition or subtraction equation, relating three whole numbers that would make it true.

Example: determining the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, and 6 + 6 = ?

Students will use number bonds and counters as a strategy for finding the missing addend. Students will become aware of the relationship between addition and subtraction. They will also use counting as it is related to addition and subtraction.

This is a College- and Career-Ready Standards showcase lesson plan.

   View Standards     Standard(s): [MA2019] (1) 8 :

8. Solve for the unknown whole number in various positions in an addition or subtraction equation, relating three whole numbers that would make it true.

Example: determining the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, and 6 + 6 = ?

[MA2019] (1) 4 :

4. Explain subtraction as an unknown-addend problem.

Example: subtracting 10 - 8 by finding the number that makes 10 when added to 8

[MA2019] (1) 2 :

2. Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20 by using concrete objects, drawings, or equations with a symbol for the unknown number to represent the problem.

[MA2019] (1) 1 :

1. Use addition and subtraction to solve word problems within 20 by using concrete objects, drawings, and equations with a symbol for the unknown number to represent the problem.

a. Add to with change unknown to solve word problems within 20.

b. Take from with change unknown to solve word problems within 20.

c. Put together/take apart with addend unknown to solve word problems within 20.

d. Compare quantities, with difference unknown, bigger unknown, and smaller unknown while solving word problems within 20.

This learning activity will provide online practice with solving word problems involving situations of adding to, taking from, taking apart, and comparing with unknowns in all positions. The students will use strategies they learned to solve the problems presented to them in this engaging online game. This is a helpful tool to measure the students' application of skills.

This activity results from the ALEX Resource Development Summit.

   View Standards     Standard(s): [MA2019] (1) 2 :

2. Solve word problems that call for addition of three whole numbers whose sum is less than or equal to 20 by using concrete objects, drawings, or equations with a symbol for the unknown number to represent the problem.

[MA2019] (1) 8 :

8. Solve for the unknown whole number in various positions in an addition or subtraction equation, relating three whole numbers that would make it true.

Example: determining the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, and 6 + 6 = ?

[MA2019] (1) 1 :

1. Use addition and subtraction to solve word problems within 20 by using concrete objects, drawings, and equations with a symbol for the unknown number to represent the problem.

a. Add to with change unknown to solve word problems within 20.

b. Take from with change unknown to solve word problems within 20.

c. Put together/take apart with addend unknown to solve word problems within 20.

d. Compare quantities, with difference unknown, bigger unknown, and smaller unknown while solving word problems within 20.

This learning activity will guide students through solving story problems. It will help the students unpack simple word problems with unknowns in all positions.  The students will use different strategies to solve problems. It will encourage the students to make sense of problems. This learning activity will engage the students so that they will feel confident in solving a variety of story problems.

This activity results from the ALEX Resource Development Summit.

   View Standards     Standard(s): [MA2019] (1) 8 :

8. Solve for the unknown whole number in various positions in an addition or subtraction equation, relating three whole numbers that would make it true.

Example: determining the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, and 6 + 6 = ?

[MA2019] (1) 6 :

6. Add and subtract within 20.

a. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by counting on.

b. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by making ten.

c. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by decomposing a number leading to a ten.

Example: 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9

d. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by using the relationship between addition and subtraction.

Example: Knowing that 8 + 4 = 12, one knows 12 - 8 = 4.

e. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by creating equivalent but easier or known sums.

Example: adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13

This learning activity will provide online practice with composing and decomposing numbers. The students will use strategies learned to determine the unknown whole number in an addition or subtraction equation relating three whole numbers. This is a helpful tool to measure the students' application of skills and help build number sense and increase fluency.

This activity results from the ALEX Resource Development Summit.

   View Standards     Standard(s): [MA2019] (1) 8 :

8. Solve for the unknown whole number in various positions in an addition or subtraction equation, relating three whole numbers that would make it true.

Example: determining the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, and 6 + 6 = ?

[MA2019] (1) 6 :

6. Add and subtract within 20.

a. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by counting on.

b. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by making ten.

c. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by decomposing a number leading to a ten.

Example: 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9

d. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by using the relationship between addition and subtraction.

Example: Knowing that 8 + 4 = 12, one knows 12 - 8 = 4.

e. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by creating equivalent but easier or known sums.

Example: adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13

This learning activity is a fun and interactive game. It will develop number sense by composing and decomposing numbers as well as building a foundation for place value skills. It can be used in whole group and small group instruction.  Before this game, the students will need to know strategies for making numbers in different ways. After the students are comfortable with this game, it can be varied by playing it with breaking into three parts. Students will have the opportunity to use several of the mathematical practices. This task allows the teacher to assess students' mathematical understanding.

This activity results from the ALEX Resource Development Summit.

   View Standards     Standard(s): [MA2019] (1) 6 :

6. Add and subtract within 20.

a. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by counting on.

b. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by making ten.

c. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by decomposing a number leading to a ten.

Example: 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9

d. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by using the relationship between addition and subtraction.

Example: Knowing that 8 + 4 = 12, one knows 12 - 8 = 4.

e. Demonstrate fluency with addition and subtraction facts with sums or differences to 10 by creating equivalent but easier or known sums.

Example: adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13

[MA2019] (1) 8 :

8. Solve for the unknown whole number in various positions in an addition or subtraction equation, relating three whole numbers that would make it true.

Example: determining the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = ? - 3, and 6 + 6 = ?

Let’s get ready to limbo! How low can you go? In order to be good at limbo, it’s important to be flexible. 2020 Arkansas Teacher of the Year, Joel Lookadoo, shows students that just as it is important to be flexible when playing limbo, it is important to be flexible when solving math problems. The worksheet that accompanies this video provides students the opportunity to practice using computational strategies to solve addition and subtraction problems within 20 with unknowns in all places.