Unit 2 — Counting, Addition, and Subtraction
Description
Unit 2 expands counting to 50 and develops fluency with addition and subtraction within 10. Students count forward from any number, compare groups of objects, and determine whether one group has more, less, or equal numbers. Subtraction is formalized as taking apart and taking from. Students use objects and drawings to represent and solve addition and subtraction word problems. The unit emphasizes flexible strategies for solving problems and building toward fluency with combinations within 5. Students continue to develop number sense through comparisons and observations of number patterns.
Essential Questions
- Why is counting important?
- How can you know a quantity without counting each object?
- How do you know if you have more or less than your partner?
- How can you explain how one end of a domino connects to another?
- What is an efficient strategy for counting teen numbers?
Learning Objectives
- Count to 50 by ones and by tens
- Count forward from any number up to 50
- Write numbers from 0 to 20
- Understand addition and subtraction concepts
- Solve addition and subtraction word problems using objects or drawings
- Add and subtract within 10
- Compare numbers using greater than, less than, and equal to
- Demonstrate fluency for addition and subtraction within 5
Supplemental Resources
- Number cards 0-50 for counting exercises
- Counters in two colors for addition and subtraction modeling
- Number lines printed on paper or laminated for reference
- Printed word problem cards at various difficulty levels
- Sorting mats with labels for grouping activities
Counting and Cardinality
Operations and Algebraic Thinking
Standards for Mathematical Practice
Students connect everyday vocabulary to strengthen understanding of mathematical terms. Students utilize reading comprehension skills by acting out or drawing the order of important events in story problems. Students create mathematical stories using numbers, pictures, and words in interactive student notebooks and read alouds.
Students work with data and make calculations involving measurements and other data across all modules. Students develop understanding through observing patterns and analyzing information related to physical and natural phenomena.
Students connect money as a means for helping people buy things they need or want. Students complete independent and partner projects to plan and market a good or service, developing economic literacy.
Formative Assessments
- Classwork on counting sequences and numeral formation
- Exit tickets with simple addition or subtraction problems
- Whiteboards for quick problem solving
- Individual work on word problems with manipulatives
- Math journals showing addition and subtraction strategies
Summative Assessment
Chapter tests on counting to 50, writing numerals 0-20, solving addition and subtraction problems within 10, and comparing numbers
Benchmark Assessment
Benchmark assessments measuring counting to 50, numeral writing, and addition/subtraction fluency within 5
Alternative Assessment
Students may demonstrate counting fluency and addition/subtraction understanding through one-on-one oral counting with the teacher or by using manipulatives to show their work instead of drawing or writing. Number cards, ten frames, or objects may be provided to support problem solving and numeral identification.
IEP (Individualized Education Program)
For students with IEPs, provide hands-on manipulatives such as counters, linking cubes, or number lines to support counting, addition, and subtraction concepts, allowing students to demonstrate understanding through physical action rather than written output alone. Oral responses and teacher or aide scribing should be accepted alternatives to written numeral formation or journal entries when fine motor or language processing needs are present. Break multi-step word problems into smaller parts using visual supports such as pictures or diagrams, and provide a number line or number chart taped to the work surface for reference during counting and comparison tasks. Frequent check-ins and immediate corrective feedback during classwork will help students build accuracy and confidence with number combinations within 5 and 10.
Section 504
Students with 504 plans should be provided preferential seating during whole-group counting and problem-solving instruction to minimize distraction and support focus. Extended time on exit tickets and chapter assessments, along with a reduced-distraction environment, supports access to counting sequences and addition and subtraction tasks without penalizing processing speed. A personal number line or hundreds chart on the student's work surface can serve as a low-barrier reference tool during independent practice.
ELL / MLL
Multilingual learners should be supported with visual representations of key vocabulary such as 'more,' 'less,' 'equal,' 'add,' and 'subtract,' using pictures, gestures, and real objects to connect meaning to mathematical language used throughout this unit. Directions for counting tasks and word problems should be given in short, simple steps, accompanied by modeling and visual demonstrations before students work independently. When possible, allow students to use their home language to explain their thinking about number comparisons or addition and subtraction strategies before transitioning to English mathematical vocabulary.
At Risk (RTI)
Students who need additional support should begin counting and comparison tasks with smaller number ranges, building toward 50 gradually as foundational understanding of one-to-one correspondence and number sequence is secured. Connecting addition and subtraction concepts to concrete, familiar situations — such as counting classroom objects or grouping manipulatives — helps activate prior knowledge and makes abstract operations more accessible. Providing structured visual supports, such as a partially completed drawing or a pre-arranged set of counters, gives students a meaningful entry point into word problems without removing the mathematical thinking.
Gifted & Talented
Students who demonstrate early mastery of counting to 50 and fluency within 5 should be challenged to explore number patterns, such as skip counting by twos or fives, and to investigate combinations that make numbers beyond 10. Encourage these students to generate their own addition and subtraction story problems and explain multiple strategies for arriving at the same answer, deepening flexible thinking about number relationships. Comparison tasks can be extended by asking students to reason about how much more or less one quantity is than another, introducing the language of difference as a bridge toward more sophisticated number sense.