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    Quarter 2Week 15WednesdayDay 73 of 180

    Week 15, Wednesday: Subtract within 20 by counting back for small · Compare how two nonfiction authors define the same

    Day 73 · 3 lessons · 140 min

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    Math

    Students will subtract within 20 by counting back for small differences and by thinking addition (fact families) for larger ones (2.OA.B.2).

    Remember?

    3 quick questions from earlier weeks · about 3 minutes

    1. 15 − 9 = ? Facts to 20
    2. Noah has 51 beads. Mia has 23. How many more does Noah have? Week 14
    3. 918 − 312 = ? Week 12

    Standards Addressed

    2.OA.B.2

    Activities

    10 min

    Warm-Up

    Mixed addition speed round: shuffle the doubles, near-doubles, and make-ten cards together (22 cards) and time one full pass. Record the time on the tracking sheet next to Monday's and Tuesday's.

    15 min

    Mini-Lesson

    Teach count back for subtracting 1, 2, or 3: for 14 - 3 say '14... 13, 12, 11' while tapping three fingers. Then teach think addition for the rest: for 15 - 8 ask, '8 plus what makes 15?' and use make ten (8 + 2 = 10, 10 + 5 = 15, so 7). For 13 - 6 use the near double (6 + 7 = 13, so 7). Write each subtraction fact next to its addition partner.

    15 min

    Practice

    Sort 12 subtraction cards into two piles, 'count back' (12-2, 15-3, 18-1, 11-3, 16-2, 20-3) and 'think addition' (15-8, 13-6, 17-9, 14-7, 12-5, 16-9). Solve each pile out loud, saying the strategy first. Then solve the think-addition pile a second time faster.

    5 min

    Wrap-Up

    Ask, 'Why is counting back a bad idea for 17 - 9?' Listen for 'too many steps, I might lose count.' Reinforce: count back for small numbers, think addition for the rest.

    Materials Needed

    index cardstimertracking sheetpaperpencil

    Related Resources

    Math Worksheets (Weeks 13-16)Math Answer Key (Weeks 13-16)

    English Language Arts

    Students will compare how two nonfiction authors define the same key words and will use a children's dictionary (RI.2.4, RI.2.9, L.2.4e).

    Remember?

    3 quick questions from earlier weeks · about 3 minutes

    1. Name two things you can compare in two versions of the same story. Week 14
    2. 'The wind blew hard, so the tree fell.' What happened because of the wind? Week 12
    3. Put the two words together: sun + flower. Grammar and spelling

    Standards Addressed

    RI.2.4RI.2.9L.2.4e+1 more

    Activities

    15 min

    Read-Aloud

    Read 'Sharks' by Gail Gibbons. Ask your child to listen for key words they already know from Anne Schreiber's book (gills, prey, fins) and to raise a hand when Gibbons explains a word with a labeled diagram instead of a glossary.

    Sharks by Gail Gibbons
    10 min

    Mini-Lesson

    Put the two books side by side and look up 'gills' in each. Talk about how Schreiber uses a glossary and Gibbons uses labels on a drawing, and that both help a reader. Then look up 'gill' in a children's dictionary and compare all three meanings.

    National Geographic Readers: Sharks! by Anne SchreiberSharks by Gail Gibbonschildren's dictionary
    15 min

    Guided Reading

    Your child reads two pages of Gail Gibbons with you, choosing three key words they cannot define. For each, they try the sentence first, then the diagram, then the dictionary, and tell you which one worked.

    Sharks by Gail Gibbonschildren's dictionarypaperpencil
    15 min

    Writing Workshop

    Your child adds a third reason from Gail Gibbons's book using 'and' to join two facts: 'Sharks have been on Earth for millions of years, and some are as small as your hand.' They then circle every linking word in their draft (because, and, also).

    writing folderpencil
    10 min

    Phonics: Dictionary Skills

    Teach guide words: the two words at the top of a dictionary page tell the first and last words on it. Open the children's dictionary to any page, read the guide words, and have your child decide whether fin, tooth, gill, and prey would be on that page, before or after.

    children's dictionaryindex cards

    Materials Needed

    National Geographic Readers: Sharks! by Anne SchreiberSharks by Gail Gibbonschildren's dictionarypaperpencilwriting folderindex cards

    Related Resources

    ELA Worksheets (Weeks 13-16)ELA Answer Key (Weeks 13-16)

    Science

    Students will compare sketches against the criteria list and choose one design to build, explaining the choice (K-2-ETS1-2).

    This week's reading: Plan It, Sketch It

    Standards Addressed

    K-2-ETS1-2

    Activities

    5 min

    Review

    Lay the three sketches side by side with the Problem Brief. Ask: 'Which ones meet all three criteria? Which uses only recycling-bin materials?' Introduce the word 'prototype': the first version you build to try out an idea.

    20 min

    Deeper Investigation

    Make a Decision Chart: rows are the three sketches, columns are the criteria plus 'easy to build'. Put a check or an X in each box, count the checks, and pick the winner (if there is a tie, your child breaks it and says why). Then make the final build plan: a bigger, neater drawing with every material listed on the side, a step list of 1, 2, 3, 4, and a 'test plan' line: 'Tilt the table and put 8 crayons in.'

    Engineering Notebookpencilrulercolored pencils
    5 min

    Data Discussion

    Ask: 'Did the chart pick the same design you liked most? Why or why not?' Point out that engineers use criteria so their choice is fair, not just a favorite.

    Materials Needed

    Engineering Notebookpencilrulercolored pencils

    Related Resources

    Science Worksheets (Weeks 13-16)Science Answer Key (Weeks 13-16)

    Today's Practice

    One page for your child for each lesson. Answers are for grown-ups.

    Math practice · Week 15 · Wednesday

    I can subtract by counting back or thinking addition.

    Look: 16 − 7

    1. Think: 7 + ? = 16.
    2. 7 + 3 = 10. 10 + 6 = 16. 3 + 6 = 9.
    3. So 16 − 7 = 9.

    Count back. Tap one finger for each number.

    1. 13 − 2 = ____
    2. 17 − 3 = ____
    3. 19 − 2 = ____

    Think addition. Fill in both blanks.

    1. 14 − 6 = ____ (6 + ____ = 14)
    2. 13 − 8 = ____ (8 + ____ = 13)
    3. 17 − 8 = ____ (8 + ____ = 17)
    4. 11 − 7 = ____ (7 + ____ = 11)

    Challenge

    • Why is counting back a hard way to solve 15 − 9?
    How did it go? Great Okay Tricky

    ELA practice · Week 15 · Wednesday

    I can use guide words in a dictionary.

    Look: guide words

    1. Guide words are at the top of a dictionary page.
    2. They show the first and last words on that page.
    3. Page with fan and fog: fin is between them, so it is on the page.

    The guide words are fan and fog. Where is each word?

    1. fishon the pagebeforeafter
    2. eggon the pagebeforeafter
    3. foxon the pagebeforeafter
    4. gillon the pagebeforeafter

    Think about the two shark books you read.

    1. Name one key word that both books used.
    2. Join the two facts with and: Sharks have fins. Sharks have gills.

    Challenge

    • How did each author help you learn a key word?
    How did it go? Great Okay Tricky

    Science practice · Week 15 · Wednesday

    I can use criteria to choose the best design.

    Make a decision chart. Put a check or an X in each box. Count the checks.

    SketchCriterion 1Criterion 2Criterion 3Easy to buildChecks
    1. The winning design is ____.
    2. Did the chart pick the one you liked most? Why or why not?

    Answer the questions.

    1. What is a prototype?
    2. My test plan: ____.
    How did it go? Great Okay Tricky