Ahava~Love Assembly

Grade 2 Mathematics Week 3 | Teacher Guide

Grade 2 | MATHEMATICS

WEEK 3 • TEACHER GUIDE AND ANSWER KEY • DAYS 11–15

Read each lesson aloud with the child and model the worked example before practice. Do not show this key during practice. Accept oral, drawn or written answers where the child cannot yet write the whole answer. On Day 15, read aloud if needed but give no hints.

Week 3 Student Textbook | Week 3 Practice Workbook | Week 3 Teacher Guide | Week 2 Student Textbook | Week 4 Student Textbook | Grade 2 index

Day 11: Even and Odd: Make Pairs

Standard: Grade 2 Math Standard 3, 2.OA.C.3

Worked example: Is 9 even or odd? Worked answer: 9 is odd.

  1. Even (6 pairs, none left over).
  2. 1 (7 pairs and 1 left over).
  3. Even.
  4. 11, 13, 15, 17, 19.
  5. Every shoe had a partner, with none left over. A number that makes pairs with none left over is even. Accept any answer about pairs with nothing left over.

Teaching note: Use real objects for every question. A child who answers from the last digit only should still show the pairs once, so the rule has meaning.

Day 12: Even Numbers Are Doubles

Standard: Grade 2 Math Standard 3, 2.OA.C.3a

Worked example: Write 10 as a sum of two equal addends. Worked answer: 10 = 5 + 5.

  1. 8 = 4 + 4.
  2. 16 = 8 + 8.
  3. 18.
  4. 12 (12 = 6 + 6).
  5. 5 and 6 are not equal addends. 11 cannot be split into two equal groups, so it is odd. Accept any answer that says the two parts are not the same.

Teaching note: Doubles facts help with fluency within 20. Practice saying the doubles aloud: 1 + 1 through 10 + 10.

Day 13: Arrays: Rows and Columns

Standard: Grade 2 Math Standard 4, 2.OA.C.4

Practice record: Arrays, printed on the Week 3 Practice Workbook.

Worked example: An egg tray has 2 rows with 5 eggs in each row. How many eggs are there? Worked answer: There are 10 eggs.

  1. 9 (3 + 3 + 3).
  2. 8 (2 + 2 + 2 + 2).
  3. 20.
  4. 6 (3 + 3), with 2 rows of 3 drawn.
  5. Each row has 4, and there are 5 rows, so add 4 once for every row: 4 + 4 + 4 + 4 + 4 = 20. Accept any answer that adds one 4 per row.

Teaching note: Let the child build each array with counters before answering. Keep arrays at 5 by 5 or smaller.

Day 14: Write an Equation for an Array

Standard: Grade 2 Math Standard 4, 2.OA.C.4a

Practice record: Garden beds, printed on the Week 3 Practice Workbook.

Worked example: Write an equation for a window with 2 rows of 4 panes. Worked answer: 4 + 4 = 8.

  1. 5 + 5 + 5 = 15.
  2. 4 + 4 + 4 + 4 = 16.
  3. 2 + 2 + 2 + 2 + 2 = 10.
  4. The pepper bed (16).
  5. By rows: 5 + 5 + 5 = 15. By columns: 3 + 3 + 3 + 3 + 3 = 15. The same plants are counted either way, so the total is the same. Accept both equations with a reason about counting the same plants.

Teaching note: Point out that the same array can be read by rows or by columns. This prepares for multiplication in Grade 3.

Day 15: Independent Check: Even, Odd and Arrays

Standard: Grade 2 Math Standard 3, 2.OA.C.3; Grade 2 Math Standard 3, 2.OA.C.3a; Grade 2 Math Standard 4, 2.OA.C.4; Grade 2 Math Standard 4, 2.OA.C.4a

Practice record: Muffin pan, printed on the Week 3 Practice Workbook.

Worked example: Is 13 even or odd? Worked answer: 13 is odd.

  1. Even.
  2. 14 = 7 + 7.
  3. 4 + 4 + 4 = 12.
  4. 12.
  5. Yes. 12 is even, so it splits into two equal groups: 12 = 6 + 6. Each child gets 6. Accept any answer that uses 12 being even or shows 6 and 6.

Teaching note: Independent check: read aloud if needed, but do not help with the answers. Counters may be used.

Week 3 Student Textbook | Week 3 Practice Workbook | Week 3 Teacher Guide | Week 2 Student Textbook | Week 4 Student Textbook | Grade 2 index