Grade 2 Number & Operations Benchmarks

Compare and Represent whole numbers up to 1000 with an emphasis on place value and equality

Benchmarks

Examples
1. 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


2. Use place value to describe whole numbers between 10 and 1000 in terms of hundreds, tens, and ones. Know that 100 is 10 tens, and 1000 is 10 hundreds.

Writing 853 is a shorter way of writing
8 hundreds + 5 tens + 3 ones

3. Find 10 more or 10 less than a given three-digit number. Find 100 more or 100 less than a given three-digit number.

Find the number that is 10 less than 382 and the number that is 100 more than 382.
4. Round numbers up to the nearest 10 and 100 and round numbers down to the nearest 10 and 100.

If there are 17 students in the class and granola bars come 10 to a box, you need to buy 20 bars (2 boxes) in order to have enough bars for everyone.
5. Compare and order whole numbers up to 1000.


Demonstrate mastery of addition and subtraction basic facts: add and subtract one-and two-digit numbers in real-world and mathematical problems.
1. Use strategies to generate addition and subtraction facts including making tens, fact families, doubles plus or minus one, counting on, counting back, and the commutative and associative properties. Use the relationship between addition and subtraction to generate basic facts.

Use the associative property to make tens when adding
5 + 8 = (3 + 2) + 8 = 3 + (2 + 8) = 3 + 10 = 13

2. Demonstrate fluency with basic addition facts and related subtraction facts.


3. Estimate suns and differences up to 100.

Know that 23 + 48 is about 70.
4. Use mental strategies and algorithms based on knowledge of place value and equality to add and subtract two-digit numbers. Strategies may include decomposition, expanded notation, and partial sums and differences.

Use decomposition, 78 + 42, can be thought of as: 78 + 2 + 20 + 20 = 80 + 20 + 20 = 100 + 20 = 120 and using expanded notation, 34 - 21 can be thought of as 30 + 4 - 20 - 1 = 30 - 20 + 4 - 1 = 10 + 3 = 13.
5. Solve real-world and mathematical addition and subtraction problems involving whole numbers with up to 2 digits.


6. Use addition and subtraction to create and obtain information from tables, bar graphs and tally charts.