Use place value understanding to round whole numbers to the nearest 10 or 100.

[divider] [/divider] Students are able to… 

  • Determine the tens or hundreds a number falls between when given a two-digit or three-digit number.
  • Plot two-digit and three-digit numbers on a number line.
  • Explain which ten or hundred a number is closer to and why.
  • Discuss patterns when rounding to the nearest ten or hundred.

[divider] [/divider] Students are able to…because teachers:

  • Ask questions that have students determine the tens/hundreds that a number falls between.
  • Provide opportunities for the students to place numbers on a number line.
  • Pose tasks where students are asked to justify how and why they rounded numbers to the nearest ten or hundred.

[divider] [/divider] Questions to ask students:

  • What two tens/hundreds does that value fall between?
    • Sample answer that indicates understanding: 72 would be between the tens 70 and 80
  • What midpoint number would you use to help you round that value?  How would it help you?
    • Sample answer that indicates understanding: 349 would be between the hundreds 300 and 400, and the midpoint value would be 350.  Since 349 is less than the midpoint of 350, it would round to 300.
  • What is the greatest number that would round to that same value?  What is the lowest number?
    • Sample answer that indicates understanding: The greatest number that would also round to 60 is 64, the lowest is 55.

[divider] [/divider] FSA Notes

Cognitive Complexity Level: 1 – Recall

Achievement Level Descriptors:

2- uses place value understanding to round a three-digit number to the nearest 10

3- uses place value understanding to round whole numbers (up to 1,000) to the nearest 10 or 100

4- uses place value understanding to round whole numbers to both the nearest 10 and 100 where the digit to the left is also affected (e.g., round 199 to the nearest ten)

5- determines missing original number when given a number that has been rounded

Assessment Limits:

Items may contain whole numbers up to 1,000.

[divider] [/divider] Additional Resources:

Additional in depth content knowledge

Blog Post

Video: Round to the Nearest Ten Using a Number Line

Video: Round to the Nearest Hundred Using a Number Line

Video:  Round to the Nearest Ten or Hundred in Real World Situations

[divider] [/divider] Sample Formative Assessment Tasks:

[divider] [/divider]   Resources/Tasks to Help Your Child at Home

  • Rather than encouraging the memorization of rounding rules/raps, reinforce the use of number sense and place value; rounding is all about finding a “friendly” number that is close in value.

 

  • Challenge your child to round numbers you come across in everyday life. For example: miles on road signs, speed limits, temperatures, etc.  Have them identify the benchmark numbers and midpoint used to determine the rounded value.

 

  • Provide real-world opportunities to estimate sums or differences, including two-step problems. For example, rounding to estimate total cost of items at a store and estimating change that will be received; or rounding to estimate nutritional information of ingredients.