Standards-based assessment and Instruction

Riley is reading a book that has twenty pages. Riley reads twelve pages before lunch. Riley reads five pages after lunch. Riley says she read seventeen pages in her book. Is Riley correct? Show all your mathematical thinking.

### Strategies for Addition and Subtraction Unit

The Strategies for Addition and Subtraction Unit involves understanding the processes of addition and subtraction in order to solve problems and answer questions such as:

• If we know all of the parts, how can we find the whole?
• If we know the whole and one of the parts, how can we find the missing part?
• Given an equation, can you create an addition or subtraction situation to match it? How can you prove it matches the equation?
##### Standards covered: 1.3A, 1.3D, 1.3E, 1.3F, 1.5D, 1.5G

This task requires students to solve addition problems in which the result is unknown and compare the sum to a given number. Students also need to have number sense to 20.

### TEKS Mathematical Process Standards

• 1.1A Apply mathematics to problems arising in everyday life, society, and the workplace.
• 1.1B Use a problem-solving model that incorporates analyzing given information, formulating a plan or strategy, determining a solution, justifying the solution, and evaluating the problem-solving process and the reasonableness of the solution.
• 1.1C Select tools, including real objects, manipulatives, paper and pencil, and technology as appropriate, and techniques, including mental math, estimation, and number sense as appropriate, to solve problems.
• 1.1G Display, explain, and justify mathematical ideas and arguments using precise mathematical language in written or oral communication.

### Underlying Mathematical Concepts

• Number sense to 17 (20)
• Comparison
• Before/After

• Diagram/Key
• Number line
• Tally chart
• Table

### Formal Mathematical Language and Symbolic Notation

• Model
• Diagram/Key
• Number line
• Tally chart
• Table
• Total/Sum
• Odd/Even
• More than (>)/Greater than (>)/Less than (<)
• Equivalent/Equal to
• Tens, ones
• Dozen
• Halves, half of
• a.m., p.m.
• Equal shares

### Possible Solutions

Yes, Riley is correct.

### Possible Connections

Below are some examples of mathematical connections. Your students may discover some that are not on this list.

• Riley read 7 more pages before lunch than after lunch.
• She read an odd number pages after lunch and an even number of pages before lunch.
• She needs to read 3 more pages to finish the book.
• Solve more than one way to verify answer.
• 12 pages is a dozen.
• 17 is an odd total of pages read, so she could not read half before and half after lunch.
• Before noon is a.m.
• After noon is p.m.
• 12 > 5 and 5 < 12
• She could have read 10 pages before and 10 pages after lunch, making it an equal share.

### Scoring Rationales and Corresponding Anchor Papers

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## Here's What People Are Saying

The Exemplars program is designed to assess students' problem-solving and mathematical-communication skills. It also supports higher-level thinking and extension of mathematical reasoning.

S. Dement
Teacher

Converse, TX

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