Ahava~Love Assembly

Grade 2 Mathematics Week 16 | Teacher Guide

Grade 2 | MATHEMATICS

WEEK 16 • TEACHER GUIDE AND ANSWER KEY • DAYS 76–80

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 80, read aloud if needed but give no hints.

Week 16 Student Textbook | Week 16 Practice Workbook | Week 16 Teacher Guide | Week 15 Student Textbook | Grade 2 index

Day 76: Repeating Patterns

Standard: Grade 2 Math Standard 5, 2.OA.D.5

Practice figure: Pattern strips A, B and C, printed on the Week 16 Practice Workbook. A: square. B: triangle. C: square, then circle.

Worked example: What comes next? clap, stomp, clap, stomp, clap Worked answer: stomp

  1. A square.
  2. triangle, triangle, circle
  3. A square, then a circle.
  4. red, blue, blue
  5. Once you know the part that repeats, you say it again and again in the same order, so you know what comes next. Accept any answer about repeating the same part in order.

Teaching note: Build each strip with real objects such as buttons, blocks or spoons, and have the child say the pattern aloud.

Day 77: Number Patterns

Standard: Grade 2 Math Standard 5, 2.OA.D.5

Practice figure: Number strips A, B, C and D, printed on the Week 16 Practice Workbook. A: 25, 30. B: subtract 2 (next 22). C: 400. D: 94, add 10.

Worked example: What is the rule? 2, 4, 6, 8 Worked answer: Add 2 each time.

  1. 25 and 30.
  2. Subtract 2 each time (count back by 2s).
  3. 400.
  4. 94. The rule is add 10 each time.
  5. The rule is add 3 each time, not add 2. 12 + 3 = 15, so the next number is 15. Accept 15 with the add-3 rule.

Teaching note: Use a hundred chart. Have the child color each number in a pattern to see the equal steps.

Day 78: Make a Pattern and Describe Its Rule

Standard: Grade 2 Math Standard 5, 2.OA.D.5

Worked example: A pattern is block, ball, block, ball. What is the part that repeats? Worked answer: block, ball

  1. spoon, fork, fork
  2. 8 forks (2 + 2 + 2 + 2).
  3. 15 beads (3 + 3 + 3 + 3 + 3).
  4. 90, 80, 70, 60, 50
  5. If the pattern breaks its rule even once, no one can tell what should come next, so it cannot be extended. Accept any answer about being able to tell what comes next.

Teaching note: Results vary. Let the child be the helper for a pattern you make too. Use the observation checklist below.

Hands-on task observation checklist (Make a pattern for a helper to extend). Check each item you observe. Four or five items shows the child met the task goal; two or three means repeat the task with support.

  • ☐ Child used at least two kinds of objects.
  • ☐ The part that repeats appears at least 3 times.
  • ☐ Child recorded the pattern.
  • ☐ Child described the part that repeats in words.
  • ☐ Child checked the helper’s next 3 objects against the pattern.

Day 79: Mixed Review: Facts, Time and Money

Standard: Grade 2 Math Standard 2, 2.OA.B.2; Grade 2 Math Standard 23, 2.M.C.23; Grade 2 Math Standard 24, 2.M.C.24

Practice figure: Clocks A and B, and a set of coins, printed on the Week 16 Practice Workbook. Clock A shows 3:45 and Clock B shows 10:15. The coins total 67¢.

Worked example: Solve 9 + 5 by making a ten. Worked answer: 14.

  1. 15. Strategies vary, such as 8 + 2 = 10 and 10 + 5 = 15, or 7 + 7 = 14 and 1 more is 15.
  2. 8, because 6 + 8 = 14.
  3. Clock A: 3:45 (quarter to 4). Clock B: 10:15 (quarter past 10).
  4. 67¢ (25 + 25 + 10 + 5 + 1 + 1).
  5. Addition and subtraction are related. If 9 + 6 = 15, then taking 9 away from 15 leaves 6, so 15 – 9 = 6. Accept any answer that uses the related fact to get 6.

Teaching note: Keep the fact practice quick and oral. If a fact takes a long time, show the strategy with a ten-frame or counters.

Day 80: Independent Check: Cumulative Review

Standard: Grade 2 Math Standard 8, 2.NBT.A.8; Grade 2 Math Standard 12, 2.NBT.B.12; Grade 2 Math Standard 14, 2.NBT.B.14; Grade 2 Math Standard 20, 2.M.A.20; Grade 2 Math Standard 23, 2.M.C.23; Grade 2 Math Standard 24, 2.M.C.24; Grade 2 Math Standard 25, 2.G.A.25

Practice figure: Shape W, printed on the Week 16 Practice Workbook. Shape W is a pentagon.

Worked example: What is the value of the 3 in 362? Worked answer: 300.

  1. 500 + 7 (or 500 + 0 + 7). The 5 has a value of 500 (5 hundreds).
  2. 356. Check: 356 + 247 = 603.
  3. 4 inches longer.
  4. 63¢. It will be 5:00.
  5. A pentagon. It is a closed shape with 5 straight sides and 5 corners. Accept pentagon with a reason about 5 sides or 5 corners.

Teaching note: Independent check: read aloud if needed, but give no hints. This check reviews standards from Weeks 1 to 15.

Week 16 Student Textbook | Week 16 Practice Workbook | Week 16 Teacher Guide | Week 15 Student Textbook | Grade 2 index

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