Second Grade Math Core Standards

Question 1

2.OA.1

Answer 1

Second Grade Operations and Algebraic Thinking #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, for example, by using drawings and equations with a symbol for the unknown number to represent the problem.

EX. A pencil and a sticker

Task

A pencil costs 59 cents, and a sticker costs 20 cents less. How much do a pencil and a sticker cost together?

Question 2

2.OA.2

Answer 2

Second Grade Operations and Algebraic Thinking #2 Fluently add and subtract within 20. a. Add and subtract within 20 using mental strategies such as counting on; making ten (for example, 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (for example, 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9); using the relationship between addition and subtraction (for example, knowing that 8 + 4 = 12, one knows 12 – 8 = 4); and creating equivalent but easier or known sums (for example, adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13). b. By the end of Grade 2, know from memory all sums of two one-digit numbers.

EX. Hitting the Target Number

https://tasks.illustrativemathematics.org/content-standards/2/OA/B/2/tasks/1396Materials

Number cards labeled 1-10 (attached as a PDF)

Actions

Begin by playing the game as a whole class to demonstrate the rules and for students to illustrate the range of possible strategies.

Have a student pick 5 number cards from the cards labeled 1 through 10. Then, have another student pick a “Target Number” between 10 through 20. Students must add and/or subtract 2 or more of the 5 number cards to arrive at the “target” number.

As students present the different number combinations for the “target” number, write their expressions on the board and have them explain how they were able to mentally come up with the solution.

As students explain their reasoning, name the strategies they used. For example, look for students making fives (e.g. 6 + 8 = 5 + 1 + 5 +3= 10 + 4 = 14) and tens (9 + 8 = 10 + 7), and using known facts (e.g. 8 + 8 is 16 so 8 + 7 is one less than 16) to encourage flexible thinking about the relationship among the facts.

When students understand how the game works, they can play in pairs, checking each other’s solutions.

Solution

Suppose the five number cards selected are 5, 3, 8, 1, and 9 and a target number is 16.

5 + 3 + 8. 5 and 3 is 8 and doubles 8 is 16.

Another strategy:

Break apart the 8 into 5 and 3. Add the two 5s to make 10 and the two 3s to make 6. Then add 10 and 6 to make 16.

Question 3

2.OA.3

Answer 3

Second Grade Operations and Algebraic Thinking #3 Determine whether a group of objects (up to 20) has an odd or even number of members, (for example, by pairing objects or counting them by twos). Write an equation to express an even number as a sum of two equal addends.

EX. Buttons Odd and Even

Count out 20 buttons.

Take 8 buttons and count them by twos to determine if there is an even or odd amount. Write an equation showing if it is even or odd.

Take 13 buttons and count them by twos to determine if there is an even or odd amount. Write an equation showing if it is even or odd.

Take 18 buttons and count them by twos to determine if there is an even or odd amount. Write an equation showing if it is even or odd.

Question 4

2.OA.4

Answer 4

Second Grade Operations and Algebraic Thinking #4 Use addition to find the total number of objects arranged in rectangular arrays with up to 5 rows and up to 5 columns; write an equation to express the total as a sum of equal addends.

EX. Counting Dots in Arrays

Question 5

2.NBT.1

Answer 5

Second Grade Number and Operations in Base Ten #1 Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; for example, 706 equals 7 hundreds, 0 tens, and 6 ones. Understand the following as special cases: a. 100 can be thought of as a bundle of ten tens called a “hundred.” b.The numbers 100, 200, 300, 400, 500, 600, 700, 800, 900 refer to one, two, three, four, five, six, seven, eight, or nine hundreds (and 0 tens and 0 ones).

EX. https://tasks.illustrativemathematics.org/content-standards/2/NBT/A/1/tasks/157

Question 6

2.NBT.2

Answer 6

Second Grade Number and Operations in Base Ten #2 Count within 1,000; skip-count by fives, tens, and hundreds.

EX. https://tasks.illustrativemathematics.org/content-standards/2/OA/A/1/tasks/1309

Question 7

2.NBT.3

Answer 7

Second Grade Number and Operations in Base Ten #3 Read and write numbers to 1,000 using base-ten numerals, number names, and expanded form.

https://tasks.illustrativemathematics.org/content-standards/2/NBT/A/1/tasks/1236

Question 8

2.NBT.4

Answer 8

Second Grade Number and Operations in Base Ten #4 Compare two three-digit numbers based on meanings of the hundreds, tens, and ones digits, using >, =, and < symbols to record the results of comparisons.

EX. https://tasks.illustrativemathematics.org/content-standards/2/NBT/A/4/tasks/1237

Question 9

2.NBT.5

Answer 9

Second Grade Number and Operations in Base Ten #5 Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.

EX. https://tasks.illustrativemathematics.org/content-standards/K/CC/A/1/tasks/360

Question 10

2.NBT.6

Answer 10

Second Grade Number and Operations in Base Ten #6 Add up to four two-digit numbers using strategies based on place value and properties of operations.

EX. https://tasks.illustrativemathematics.org/content-standards/2/NBT/B/6/tasks/755

Question 11

2.NBT.7

Answer 11

Second Grade Number and Operations in Base Ten #7 Add and subtract within 1,000 using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method. Understand that in adding or subtracting three-digit numbers, one adds or subtracts hundreds and hundreds, tens and tens, and ones and ones, and that it is sometimes necessary to compose or decompose tens or hundreds.

EX. Pose this problem to the children: We are in school 180 days. Today is the 124th day of school. How many more days until we are out of school for summer vacation? Explain how you know.

https://tasks.illustrativemathematics.org/content-standards/2/NBT/B/7/tasks/1063EX. TBD

Question 12

2.NBT.8

Answer 12

Second Grade Number and Operations in Base Ten #8 Mentally add 10 or 100 to a given number 100-900, and mentally subtract 10 or 100 from a given number 100-900.

EX. https://tasks.illustrativemathematics.org/content-standards/K/CC/A/1/tasks/360

Question 13

2.NBT.9

Answer 13

Second Grade Number and Operations in Base Ten #9 Explain why addition and subtraction strategies work, using place value and the properties of operations. Explanations may be supported by drawings or objects

EX. Saving Money

https://tasks.illustrativemathematics.org/content-standards/2/NBT/B/5/tasks/1292

Question 14

2.MD.1

Answer 14

Second Grade Measurement and Data #1 Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.

EX. Measurement - What Is it?

http://mypages.iit.edu/~smile/ma9302.html

Question 15

2.MD.2

Answer 15

Second Grade Measurement and Data #2 Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.

EX. Measurement - What is it?

http://mypages.iit.edu/~smile/ma9302.html

Question 16

2.MD.3

Answer 16

Second Grade Measurement and Data #3 Estimate lengths using units of inches, feet, centimeters, and meters.

EX. Time to Move

This game asks students to move fish to a new home. They must measure the fish and then determine which tank it should go in based on its length.

Question 17

2.MD.4

Answer 17

Second Grade Measurement and Data #4 Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit. For example, after measuring a pencil and a crayon, a student uses the measurements to determine that the pencil is two inches longer than the crayon.

EX. Find Someone

This lesson is designed so that students find someone in their class who matches a description by using a shape, measurement, or number.

Question 18

2.MD.5

Answer 18

Second Grade Measurement and Data #5 Use addition and subtraction within 100 to solve word problems involving lengths that are given in the same units. For example, use drawings (such as drawings of rulers) and equations with a symbol for the unknown number to represent the problem.

EX. Frog and Toad on the number line

https://tasks.illustrativemathematics.org/content-standards/2/MD/B/6/tasks/1081

Question 19

2.MD.6

Answer 19

Second Grade Measurement and Data #6 Represent whole numbers as lengths from 0 on a number line diagram with equally spaced points corresponding to the numbers 0, 1, 2… Represent whole number sums and differences within 100 on a number line diagram.

EX. Frog and Toad on the number line

https://tasks.illustrativemathematics.org/content-standards/2/MD/B/6/tasks/1081

Question 20

2.MD.7

Answer 20

Second Grade Measurement and Data #7 Tell and write time from analog and digital clocks to the nearest five minutes, using a.m. and p.m.

EX. Ordering Time

https://tasks.illustrativemathematics.org/content-standards/2/MD/C/7/tasks/1069

Question 21

2.MD.8

Answer 21

Second Grade Measurement and Data #8 Solve word problems involving dollar bills, quarters, dimes, nickels, and pennies, using $ and ¢ symbols appropriately. For example, if you have 2 dimes and 3 pennies, how many cents do you have?

EX. Alexander, who used to be rich last saturday

https://tasks.illustrativemathematics.org/content-standards/2/MD/C/8/tasks/1314

Question 22

2.MD.9

Answer 22

Second Grade Measurement and Data #9 Generate measurement data by measuring lengths of several objects to the nearest whole unit, or by making repeated measurements of the same object. Show the measurements by making a line plot, where the horizontal scale is marked off in whole-number units.

EX. Growing Bean Plants

https://tasks.illustrativemathematics.org/content-standards/1/OA/A/1/tasks/1086

Question 23

2.MD.10

Answer 23

Second Grade Measurement and Data #10 Draw a picture graph and a bar graph (with single-unit scale) to represent a data set with up to four categories. Solve simple put-together, take-apart, and comparison problems using information presented in a bar graph.

EX. Favorite Ice Cream Flavor

https://tasks.illustrativemathematics.org/content-standards/1/MD/C/4/tasks/506

Question 24

2.G.1

Answer 24

Second Grade Geometry #1 Recognize and draw shapes having specified attributes, such as a given number of angles or a given number of equal faces. Sizes are compared directly or visually, not compared by measuring. Identify triangles, quadrilaterals, pentagons, hexagons, and cubes.

EX. Polygons

https://tasks.illustrativemathematics.org/content-standards/2/G/A/1/tasks/1506

Question 25

2.G.2

Answer 25

Second Grade Geometry #2 Partition a rectangle into rows and columns of same-size squares and count to find the total number of squares.

Ex. Representing half of a rectangle

Question 26

2.G.3

Answer 26

Second Grade Geometry #3 Partition circles and rectangles into two, three, or four equal shares; describe the shares using the words halves, thirds, half of, a third of, etc.; and describe the whole as two halves, three thirds, or four fourths. Recognize that equal shares of identical wholes need not have the same shape.

ex. Which pictures represent one half?
https: //tasks.illustrativemathematics.org/content-standards/2/G/A/3/tasks/826