2.MD.6: Number Line Diagrams

I can represent whole numbers as lengths from 0 on a number line diagram.

What Your Child Needs to Know

In this standard, your child will learn to use number lines as a visual tool for representing numbers and solving addition and subtraction problems. They'll understand that each number on a number line represents a specific distance from zero, and that these distances can be added or subtracted by moving along the line.

Number lines are powerful visual models that help children develop number sense and understand the relationships between numbers. This skill builds on their previous work with counting and basic operations, and it prepares them for more advanced concepts like fractions on a number line in later grades.

Real World Practice

Visual models and hands-on activities

Number Line Models to Explore

  • Basic Number Line - A horizontal line with evenly spaced numbers, starting from 0
  • Open Number Line - A blank line where children can mark and label points as needed
  • Floor Number Line - A large-scale number line created with tape on the floor that children can physically walk on
  • Vertical Number Line - Like a thermometer or height chart, showing numbers increasing as they go up

Everyday Number Line Activities

1. Number Line Hopscotch

Create a number line on the sidewalk or driveway with chalk. Have your child hop from 0 to different numbers, counting as they go. Then practice addition by having them start at one number and hop forward a certain number of spaces. For subtraction, have them hop backward.

2. Temperature Tracking

Use a thermometer as a real-world vertical number line. Track daily temperatures for a week, marking them on a simple thermometer drawing. Discuss how much the temperature changed from day to day (addition and subtraction on a number line).

3. Number Line Board Game

Create a simple board game where players move along a path that's essentially a number line. Roll dice to determine how many spaces to move forward or backward. Include special squares that require players to move to specific positions on the number line.

4. Measuring Growth

Create a height chart on the wall (a vertical number line). Measure your child's height regularly and mark it on the chart. Discuss how much they've grown by finding the difference between measurements.

Quick Checks

Strategies and quick activities

Strategies When Your Child Struggles

1. Start with Physical Movement

If your child has trouble understanding number lines on paper, create a large floor number line with tape and have them physically walk forward for addition and backward for subtraction. This kinesthetic approach helps many children grasp the concept before moving to paper.

2. Use Consistent Starting Points

Always emphasize that we start counting from 0 on a number line. Have your child place their finger on 0 and then count spaces as they move to the right. This reinforces that numbers represent distances from 0.

3. Connect to Familiar Concepts

Relate number lines to concepts your child already understands, like counting steps or measuring with a ruler. Explain that a number line is like a ruler that can extend infinitely in both directions.

4. Use Incremental Complexity

Start with simple number lines (0-10) before introducing larger numbers. Begin with just addition (moving right) before introducing subtraction (moving left). Once those concepts are solid, combine them in mixed problems.

5-Minute Practice Activities

1. Number Line Jumps

Draw a simple number line from 0-20. Call out a starting number and an operation (e.g., "Start at 7, add 5"). Have your child place their finger on the starting number and then "jump" to the answer, counting spaces as they go.

2. Missing Number Challenge

Draw a number line with some numbers missing. Ask your child to fill in the blanks by looking at the pattern of the visible numbers.

3. Number Line Riddles

Give clues like, "I'm thinking of a number that's 3 more than 5 on the number line. What number am I?" or "I started at 12 and moved 4 spaces to the left. Where did I land?"

4. Addition and Subtraction Sort

Create simple addition and subtraction problems on cards. Have your child sort them into two piles: problems where they would move right on the number line (addition) and problems where they would move left (subtraction).

Check Progress

Track improvement

Mid-Year Expectations

By the middle of second grade, your child should be able to:

  • Locate whole numbers (0-100) on a number line
  • Understand that numbers on a number line represent distances from 0
  • Use a number line to solve simple addition problems within 100
  • Begin to use a number line to solve simple subtraction problems

End-of-Year Expectations

By the end of second grade, your child should be able to:

  • Confidently represent whole numbers (0-1000) as positions on a number line
  • Use number lines to solve addition and subtraction problems within 100
  • Create their own number lines to represent and solve problems
  • Understand that the distance between any two consecutive whole numbers is the same
  • Use number lines to represent and solve word problems

Mastery Signs

Your child has mastered this standard when they can:

  • Independently create and use number lines to represent and solve problems
  • Explain how movement on a number line relates to addition and subtraction
  • Use number lines flexibly with different scales and ranges of numbers
  • Apply number line concepts to solve real-world measurement problems
  • Connect number line representations to other mathematical models

Differentiation

Support for all learning levels

Below Grade Level

Practice activities focusing on basic number line representation and simple addition.

Download Practice Worksheet

At Grade Level

Standard practice with representing numbers and solving addition and subtraction problems on number lines.

Download Grade Level Worksheet

Above Grade Level

Challenging activities involving multi-step problems, larger numbers, and real-world applications of number lines.

Download Challenge Worksheet