## 2nd Grade Power Standards (also refer back to 1st grade skills)

2.1.1.1, 2.1.1.2, 2.1.1.3-2.1.1.5

- Read, write and represent whole numbers up to 1000. Representations may include numerals, addition, subtraction, multiplication, words, pictures, tally marks, number lines and manipulatives, such as bundles of sticks and base 10 blocks.
- Use place value to describe whole numbers between 10 and 1000 in terms of groups of hundreds, tens and ones. Know that 100 is ten groups of 10, and 1000 is ten groups of 100.
- Find 10 more or 10 less than any given three-digit number. Find 100 more or 100 less than any given three-digit number.
- Round numbers up to the nearest 10 and 100 and round numbers down to the nearest 10 and 100.
- Compare and order whole numbers up to 1000.

__Background Knowledge:__

- read, write and represent whole numbers up to 120;
- count forward and backward from any given number up to 120;
- use place value to describe whole numbers between 10 and 100 in terms of groups of tens and ones -- 56 is 5 tens and 6 ones or 4 tens and 16 ones or 56 ones or other place value based descriptions;
- find a number that is 10 more/less than a given two-digit number;
- compare and order whole numbers up to 120;
- describe the relative size of numbers; e.g., equal to, not equal to, more than, less than, fewer than, is about, is nearly.
- Use place value to describe whole numbers between 10 and 100 in terms of groups of tens and ones (56 is 5 tens and 6 ones).
- Read, write and represent whole numbers up to 120.
- Count forward and backward from any given number up to 120.
- Compare and order whole numbers up to 120.
- Describe the relative size of numbers; e.g., equal to, not equal to, more than, less than, fewer than.

__Mastery Expectations:__

- Read, write, and represent numbers up to 1,000 in a variety of ways including:

multiplication; using manipulatives;

drawing pictures;

using words--oral and written.

- Use place value to describe whole numbers up to 1,000 based on hundreds, tens, and ones, for example:

* 74 tens and 2 ones, or

* 7 hundreds and 42 ones, or

* 6 hundreds and 14 tens and 2 ones, or

* 3 hundreds and 43 tens and 12 ones, or

other place value-based descriptions.

- Find a number that is 10 more/less and 100 more/less than a given three-digit number
- Compare and order numbers to 1000

- Round any two- or three-digit number up or down to the nearest 10.
- Round any three-digit number up or down to the nearest 100.

2.1.2.3, 2.1.2.4-2.1.2.5, 2.1.2.6

- Estimate sums and differences up to 100.
- Use mental strategies and algorithms based on knowledge of place value to add and subtract two-digit numbers. Strategies may include decomposition, expanded notation, and partial sums and differences.
- Solve real-world and mathematical addition and subtraction problems involving whole numbers with up to 2 digits.
- Use addition and subtraction to create and obtain information from tables, bar graphs and tally charts.

__Background Knowledge:__

- basic fact knowledge (current grade level)
- composing and decomposing numbers up to 12
- understanding of base ten place value--tens and ones
- use a variety of manipulatives to solve addition and subtraction problems in part-part-total, adding to, taking away from, and comparing situations
- recognize the relationship between counting and addition and subtraction
- skip count by 2s, 5s, and 10s
- Use addition, subtraction and comparison skills to create and analyze bar graphs and tally charts.
- add and subtract.
- represent data using tables, charts and bar graphs.
- sort objects according to attributes.

__Mastery Expectations:__

- add and subtract multi-digit whole numbers by being flexible, efficient and accurate problem solvers.
- use a variety of solution strategies in problem solving situations.
- apply their understanding of models of addition and subtraction and relationships and properties of number.
- use estimation to find sums and differences
- use estimation to check the reasonableness of results.
- pose questions and gather data about themselves and their surroundings.
- represent data using concrete objects, pictures, and graphs.
- describe parts of the data and the set of data as a whole to determine what the data show.
- understand that titles and labels are needed on data representations so the information can be interpreted correctly.
- use the information on a graph to answer questions.

2.2.1.1

- Identify,create and describe simple number patterns involving repeated addition or subtraction, skip counting and arrays of objects such as counters or tiles. Use patterns to solve problems in various contexts.

__Background Knowledge:__

- Sort and categorize objects according to attributes.
- Creating, extending and completing repeating patterns.
- Creating, extending and completing growing and shrinking patterns.

__Mastery Expectations:__

- Recognize patterns in numbers and apply the pattern to predict what comes next in a number pattern.
- Describe the rule for a given number pattern.
- Use a given rule to extend or complete a number pattern.
- Use patterns to solve problems.

2.2.2.1-2.2.2.2

- Understand how to interpret number sentences involving addition, subtraction and unknowns represented by letters. Use objects and number lines and create real-world situations to represent number sentences.
- Use number sentences involving addition, subtraction, and unknowns to represent given problem situations. Use number sense and properties of addition and subtraction to find values for the unknowns that make the number sentences true.

__Background Knowledge:__

- Represent real-world situations involving addition/subtraction basic facts using objects and number sentences.
- Create real-world situations corresponding to number sentences.
- Determine if number sentences involving addition/subtraction are true.
- Use number sense and models to identify the missing number in an number sentence,
- Understand basic fact families (current grade level).

__Mastery Expectations:__

- Know the equal sign means "the same as"
- Solve equations with the unknown in any position:

24 + n = 103; 103 = 24 + n

n + 79 = 103: 103 = n + 79

103 - 79 = n; n = 103 - 79

103 - n = 24; 24 = 103 - n

n - 79 = 24; 24 = n - 79

20 + 52 = n + 23

- Model the above types of equations using representations including manipulatives and number lines
- Create number sentences to match given story problems
- Create story problems to match given number sentences
- Determine the truth value of number sentences
- Demonstrate an understanding of the relationship between addition and subtraction

2.3.3.1-2.3.3.2

- Tell time to the quarter-hour and distinguish between a.m. and p.m.
- Identify pennies, nickels, dimes and quarters. Find the value of a group of coins and determine combinations of coins that equal a given amount.

__Background Knowledge:__

- tell time to the hour and half-hour.
- visually discriminate between the hour hand and minute hand.
- understand the concepts of before and after.
- skip count by 5s and 10s.
- identify and know the value of pennies, nickels and dimes;
- find the value (up to one dollar) of a group of dimes, nickels and pennies;
- count by fives to at least 100;
- count by tens to at least 100;
- count forward and backward by 10 from any two-digit number.

__Mastery Expectations:__

- tell time to the quarter-hour on an analog clock.
- use the language "quarter to," "quarter after'" "fifteen minutes after" and "fifteen minutes before."
- understand the difference between am and pm.
- identify and know the value of a quarter
- find the value of a group of quarters, dimes, nickels and pennies
- use quarters, dimes, nickels and pennies to show a given amount
- use the ¢ symbol properly
- skip by 25s