In this unit, fact strategies are reviewed and extended. The following big ideas will be covered in this unit:
- Addition can be used to solve word problems involving situations such as “adding to” and “putting together”.
- Unknown facts can be figured out by using known facts, such as doubles and combinations of tens.
- When you add two numbers in any order, you’ll get the same answer.
- Numbers can be represented in many ways, such as with pictures, number lines and expanded form.
- Even number can be written as the sum of two equal addends.
- The two digits of a 2-digit number represent amounts of tens and ones.
Operations & Algebraic Thinking
2.OA.A. Represent and solve problems involving addition and subtraction.
2.OA.A.1. Use addition and subtraction within 100 to solve one- and two-step word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem.
2.OA.B. Add and subtract within 20.
See standard 1.OA.6 for a list of mental strategies.
2.OA.C. Work with equal groups of objects to gain foundations for multiplication.
2.OA.C.3. Determine whether a group of objects (up to 20) has an odd or even number of members, e.g., by pairing objects or counting them by 2s; write an equation to express an even number as a sum of two equal addends.
Number & Operations in Base Ten
2.NBT.A. Understand place value.
2.NBT.A.1. Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones. Understand the following as special cases:
2.NBT.A.1a. 100 can be thought of as a bundle of ten tens — called a “hundred.”
2.NBT.A.2. Count within 1000; skip-count by 5s, 10s, and 100s.
2.NBT.A.3. Read and write numbers to 1000 using base-ten numerals, number names, and expanded form.
2.NBT.B. Use place value understanding and properties of operations to add and subtract.
2.NBT.B.5. Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.
Explanations may be supported by drawings or objects.
2.MD.C. Work with time and money.
2.MD.C.8. Solve word problems involving dollar bills, quarters, dimes, nickels, and pennies, using $ and ¢ symbols appropriately. Example: If you have 2 dimes and 3 pennies, how many cents do you have?
© Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.
Students will have opportunities to:
Look for mathematical structures such as categories, patterns, and properties (MP. 7)
Use structures to solve problems and answer questions (MP. 7)
Create and justify rules, shortcuts, and generalizations (MP. 8)
- A number is made up of two or more parts.
- A number can be decomposed into its parts.
- Addition can be thought of as placing two or more quantities together.
- Subtraction can be thought of as taking an amount away from a given quantity, comparing two quantities, or find a missing part given the whole and the other part.
- Addition names the whole in terms of the parts.
- There are patterns to the way that numbers are formed.
- Addition can be used to solve word problems involving situations such as “comparison”.
- Subtraction can be used to solve word problems involving situations such as “taking from”, “taking apart”, and “comparison”.
- Subtraction is a missing-addend problem.
- When you add three numbers, you can pick any two numbers to add first and then add the third number. You will get the same answer.
- The three digits of a 3-digit number represent amounts of hundreds, tens and ones.
addend, addition number story, combinations of 10, divide, doubles fact, equal addends, equivalent, helper fact, label, making 10, near-doubles strategy, number model, number sentence, number story, sum; total, trade, turn-around rule, commutative property, unit box, tens, patterns, even, odd
Bold: Listed in teacher's EDM4 edition
Normal Font: not listed in teacher’s edition as a vocabulary word but will be helpful for students in explanations
The following lesson plan sequence is obtained from Everyday Mathematics 4. Each lesson is aligned with a learning objective to inform the teachers on what students should be able to at the end of the lesson. The student objective informs the students of their learning goals for the day and it should be reviewed before, during and at the end of the lesson. Each lesson includes a mathematics task that should be implemented to meet the learning objectives. Teachers can select from the practice opportunities to reinforce the learning goals of the day.
The following language supports are for English Language Learners but could also be used to support any struggling learner in mathematics. The strategies are obtained from the SIOP model. The language objectives will support students' academic language development. The sentence stems and starters provides the support many students need to be able to participate in discussions and writing about mathematics.