1.NBT.C.5 - About the Math, Learning Targets, and Increasing Rigor

Full Standard

Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

Measurement Topic

This standard is reported on the report card in these quarters as follows:

About the Math

Skills and concepts below are learning goals for this standard.

• Determine 10 more and 10 less of any two-digit number using physical tool, hundred charts, and number lines.
• Recall 10 more for any two-digit number (e.g., 32 + 10 = 42) without using a tool or representation.
• Recall 10 less for any two-digit number (e.g., 32 - 10 = 22) without using a tool or representation.
• Explain why the tens digit changes and why the ones place does not change when finding ten more or ten less.

Mental computation with nice numbers such as ten, should be encouraged so that students see the relationships that exist between and among numbers. At first students may not see the relationship of adding ten and will need to count. The hundreds chart should be used to show how to add ten. This may mean that students need to place counters on the hundreds chart between 27 and 37 and see that is adding ten. After several examples, they may begin to see a pattern that moving down the hundreds chart one row is adding 10 and moving up one row is subtracting ten. Essential vocabulary for this standard includes: add, subtract, 10 more, and 10 less (online dictionary Links to an external site., HCPSS Vocabulary Cards Download HCPSS Vocabulary Cards

Progression of Standard within Grade 1

This progression informs how to develop the standard within the grade level. This progression is provided by HCPSS Elementary Mathematics.

Progression of this Standard Across Grades

This progression is informed by the Achieve the Core Coherence Map Links to an external site.. Information is not the complete standard.

TASKS

These tasks can be used with small group or whole group instruction.

• You will need magnetic base ten blocks and blocks for partners as well. Gather students up front and build the number 16. Ask them to turn and talk about the number you made. Have them share out the number and record it on the board under the blocks.  Add another ten rod and have them tell you the new number and how they know. Record 26 next to 16. Continue adding a new ten and recording the new number on the board until you have reached 96. Ask student to look at the numbers on the board and turn and talk about what they noticed. As you come back together to debrief ask: Which digit increased? Did the ones digit ever change? How did I change the number each time? (I added a new ten rod) What does that mean? What number did I add? Do you think this will always happen as I add 10 more? Have them explore more in pairs. Tell them each to pick a number 11-19 (not 16) and build and record it with their partner. Take tens adding another ten and recording the new number each time. During debrief have each pair share their results. What happens to the tens digit when I add 10 to a number? Why? What happens to the ones digit as I add 10 to a number? Why? Turn and talk about what 42 +10 is. How do you know? Give more 2 digit plus 10 more if they need practice and have base ten available as needed. If you want to extend you could have them go beyond 100 up to 120 as they count by 10s. Complete the same activity another day for 10 less.
• Have the students gather up front and have your classroom 120 chart up. Circle any number such as 26. Ask what number is 10 more than 26? How do you know? Circle 36. Do a few more numbers and then ask "What do we notice about the numbers that we have been finding that are 10 more?" Give each pair of students a 120 chart. Have one student say a two digit number. Have their partner find it and say what number is 10 more. Have them discuss what happened to the tens place and what happened to the ones place. Have them switch roles and continue practicing finding 10 more on a 120 chart. Closure: have them write the answer to "When you are adding ten to a number what happens to the tens digit?" Complete the same activity another day for 10 less. 
• Give students a cross grid, dry erase marker, 120 chart and two 10-sided dice. Have Partner 1 roll both dice and create a two digit number and write it in the middle of the cross grid. Partner 2 will fill in 1 less, 1 more, 10 less, 10 more. Partner 1 will check on the 120 chart. They will switch rolls and continue practicing. 
• Pam said 86 is ten more than 96. Is she correct? Explain how you know. Use tools (hundred chart, etc.) in your explanation if needed.
• On the hundreds chart start at 36, if you were to move down the hundreds chart 3 spaces, what number would you land on? Did you increase or decrease your number by tens?
• Claudia started at 28. She is counting by tens what are some numbers she might say?
• How does a hundred chart help you when you are adding and subtracting 10 from a number like 57? (or multiple groups of 10 such as 30 and 50)
• Starting at 94 how many groups of 10 will you subtract to get to 24? How does knowing what is “10 less” than a number help you with this problem?

SLIDE-BASED TASKS 

  These links are HCPSS created instructional tasks. These tasks are provided in Google slides.  These tasks should be used for inspiration and resources, but instruction should start with students having the opportunity to engage with the math first (often involving physical and/or visual models) followed by discussion and explicit instruction to ensure student understanding.

Additional Tasks 

  These links provide instructional ideas connected to this standard. 

• Repeated Vacations Download Repeated Vacations
  (Utah Core Academy Lesson)
• Pumpkin Patch Download Pumpkin Patch
  (Utah Core Academy Lesson)
• Toy Sale Download Toy Sale
   (Utah Core Academy Lesson)
• Reading Books Download Reading Books
  (Utah Core Academy Lesson)
• McDonald's Adding 10 Download McDonald's Adding 10
  (Utah Core Academy Lesson)
• Pinata Candy Download Pinata Candy
  (Utah Core Academy Lesson)

Tasks From Print Resources

  These publications have been provided for each school. They are typically stored in team closets or the media center. Check with your team leader if you cannot find them. 

Print Resources

Book Thumbnail	Book Title	Grade	Pages
	Teaching Student-Centered Mathematics	K-3	More and Less on the Hundreds Chart, Activity 5.11, Page 139 Models with the Hundreds Chart, Activity 5.12, Page 139
	Mastering the Basic Facts: Addition and Subtraction	K-1
	Math In Practice Teaching First-Grade Math	1	Module 9

Centers

  These print resources can be used during independent or center time. These resources could also be used as lesson seeds.

• Around the World +10 Download Around the World +10
  (HCPSS-adapted resource)
• Around the World +10 Version 2 Download Around the World +10 Version 2
  (HCPSS-adapted resource)
• Four in a Row +10 Download Four in a Row +10
  (HCPSS-adapted resource)
• 100 Chart Magic Links to an external site. (print resource)

Independent Practice/Homework/Assessment

  These resource sheets can be used for independent practice, homework, or assessment. They are intended to reinforce procedures and concepts. They should not be used as a source of direct instruction or whole-group practice.

• Recall Ten More and Ten Less a Links to an external site.
• Recall Ten More and Ten Less b Links to an external site.
• Determine 10 More and 10 Less Using Hundred Chart Links to an external site.
• Determine 10 More and 10 Less Using Hundred Chart 2 Links to an external site.
• Determine 10 More and 10 Less Using Hundred Chart 3 Links to an external site.
• Recall 10 More and 10 Less Without Using a Tool Links to an external site.
• Recall 10 More and 10 Less Without Using a Tool 2 Links to an external site.
• Recall 10 More and 10 Less Without Using a Tool 3 Links to an external site.
• Recall 10 More and 10 Less Without Using a Tool 4 Links to an external site.
• Recall 10 More and 10 Less Without Using a Tool 5 Links to an external site.
• Recall 10 More and 10 Less and Explain How You Know Links to an external site.

Full Standard

Given a two-digit number, mentally find 10 more or 10 less than the number, without having to count; explain the reasoning used.

Measurement Topic

The standard is reported on the report card through these measurement topics. Expand the measurement topic for a description of what students who meet expectation are able to do.

First Grade Students Learning First Grade Standards by Measurement Topic

Kindergarten Students Learning 1st Grade Standards by Measurement Topic

1NBT5 Anecdotal Data Collection Tool Links to an external site.

Visit the SBIR (Standards Based Instruction and Reporting) page in Course Essentials for more information and clarification. 

Rubric (for thinking and reasoning evidence)

Use this rubric for observation and constructed responses (tasks that require explanation, justification, and/or representation).

Rubric for Tasks (pdf) Links to an external site.

Exemplars for this standard (if available)

These samples are examples of what it might look like for a student who MEETS EXPECTATIONS, is MAKING PROGRESS, and/or is MAKING LIMITED/NO PROGRESS.