Ahava~Love Assembly

Grade 2 Mathematics Week 10 | Teacher Guide

Grade 2 | MATHEMATICS

WEEK 10 • TEACHER GUIDE AND ANSWER KEY • DAYS 46–50

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 50, read aloud if needed but give no hints.

Week 10 Student Textbook | Week 10 Practice Workbook | Week 10 Teacher Guide | Week 9 Student Textbook | Grade 2 index

Day 46: Make a Line Plot from Measurements

Standard: Grade 2 Math Standard 15, 2.DA.A.15; Grade 2 Math Standard 15, 2.DA.A.15a

Practice record: Lengths of 10 crayons (inches), printed on the Week 10 Practice Workbook.

Practice figure: Line plot to complete: Lengths of 10 crayons, printed on the Week 10 Practice Workbook.

Worked example: Four pencils measure 5, 6, 6 and 7 inches. How many X marks go above 6? Worked answer: 2 X marks go above 6.

  1. 4.
  2. 4 inches.
  3. 3 crayons (two at 5 inches and one at 6 inches).
  4. 3 crayons.
  5. Every measurement needs a place on the line, so all 10 crayons are shown. If 6 were left off, one crayon would be missing. Accept any answer about showing every measurement.

Teaching note: Check the completed crayon line plot: no X above 2 or 7; 3, 4, 2 and 1 X marks above 3, 4, 5 and 6. The hands-on line plot uses the child’s own Day 38 data, so answers vary; it must show exactly 10 X marks.

Day 47: Picture Graphs and Bar Graphs

Standard: Grade 2 Math Standard 16, 2.DA.A.16; Grade 2 Math Standard 16, 2.DA.A.16a

Practice record: Favorite fruit survey, printed on the Week 10 Practice Workbook.

Practice figure: Bar graph to complete: Favorite fruit, printed on the Week 10 Practice Workbook.

Worked example: In a picture graph, the key says each picture stands for 1 child. The Swings row has 5 pictures. How many children chose swings? Worked answer: 5 children chose swings.

  1. 7 (up to the 7 on the scale).
  2. 4 more (7 – 3).
  3. 20 children (6 + 4 + 7 + 3).
  4. 3 pictures (2 + 2 + 2 = 6).
  5. The scale tells how many each bar shows. Without it, you could see which bar is tallest but not how many children chose each fruit. Accept any answer about reading the numbers.

Teaching note: Check the completed bar graph: Apples 6, Bananas 4, Grapes 7, Oranges 3 squares, each bar colored up from 0.

Day 48: Read and Compare Bar Graphs

Standard: Grade 2 Math Standard 16, 2.DA.A.16; Grade 2 Math Standard 16, 2.DA.A.16a

Practice figure: Bar graph: Books read each week, printed on the Week 10 Practice Workbook. Bar heights: Week 1, 5; Week 2, 8; Week 3, 6; Week 4, 9.

Worked example: A bar graph shows 9 red cars and 4 blue cars. How many fewer blue cars are there? Worked answer: There are 5 fewer blue cars.

  1. Week 4.
  2. 4 more (9 – 5).
  3. 13 books.
  4. 28 books (5 + 8 + 6 + 9).
  5. He is not right. Reading went up from Week 1 to Week 2, but it went down from 8 books in Week 2 to 6 books in Week 3, then up again to 9 in Week 4. Accept any answer that points out Week 3 was lower than Week 2.

Teaching note: Ask the child to make up one more how-many-more question about the graph and answer it.

Day 49: Venn Diagrams: Sort and Predict

Standard: Grade 2 Math Standard 16, 2.DA.A.16; Grade 2 Math Standard 16, 2.DA.A.16b

Practice figure: Venn diagram: Pets at home, printed on the Week 10 Practice Workbook. Dog only: Ana, Ben, Cal. Both: Dee, Eli. Cat only: Fay. Outside: Gus.

Worked example: Circle A is Has Wheels. Circle B is Can Fly. Where does an airplane go? Worked answer: In the middle, where the circles overlap.

  1. 5 children (3 in the dog circle only plus 2 in the middle).
  2. 3 children (1 in the cat circle only plus 2 in the middle).
  3. 7 children.
  4. In the cat circle only.
  5. Dee and Eli have both a dog and a cat, so they belong in both circles. The middle is the part that is in both circles. Accept any answer about belonging to both groups.

Teaching note: Questions 1 and 2 are the most common Venn error: children forget to count the middle. In the hands-on task, check that all six predictions were written in the table before any testing. Most metal objects sink, but a metal lid may float if placed flat; let the test decide.

Day 50: Independent Check: Data and Graphs

Standard: Grade 2 Math Standard 15, 2.DA.A.15; Grade 2 Math Standard 15, 2.DA.A.15a; Grade 2 Math Standard 16, 2.DA.A.16a; Grade 2 Math Standard 16, 2.DA.A.16b

Practice figure: Line plot: Lengths of 9 leaves, printed on the Week 10 Practice Workbook. X marks: 1 above 4, 3 above 5, 4 above 6, 1 above 7.

Worked example: A line plot has 3 X marks above 7 inches. How many objects are 7 inches long? Worked answer: 3 objects.

  1. 4 leaves.
  2. 6 centimeters.
  3. 4 leaves (1 at 4 and 3 at 5).
  4. 3 more votes.
  5. In the middle, where the circles overlap, because a red ball is both red and round. Accept any answer that names the middle with a reason.

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

Week 10 Student Textbook | Week 10 Practice Workbook | Week 10 Teacher Guide | Week 9 Student Textbook | Grade 2 index

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