MAFS.1.NBT.3.6 Subtract multiples of 10 in the range 10-90 from multiples of 10 in the range 10-90 (positive or zero differences), using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.

Cognitive Complexity Level: 1-Recall

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

  • Use strategies and manipulatives to subtract multiples of 10 from a multiple of 10
  • Describe patterns with subtraction
  • Subtract using mental strategies and create equations

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

  • Provide problems and materials to explore subtraction of multiples of 10 from a multiple of 10
  • Make connections to patterns with subtraction
  • Pose purposeful questions to elicit student thinking relating to patterns and strategies for subtraction

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

  • Ask:  Describe a strategy to subtract some tens from more tens? For example, 50 – 20
    • Sample answer that indicates understanding: I can start at the 50 and count back 2 tens.  50, 40, 30.  The answer is 30.
  • Ask: What happens with the digit in the ones place when you subtract some tens from more tens?
    • Sample answer that indicates understanding: In the answer there is a zero in the ones place because both of the values have a 0 in the ones place. 0 – 0 equals 0.

[divider] [/divider] Additional Resources:

Additional in depth content knowledge

Video: Subtracting Multiples of 10

https://www.youtube.com/watch?v=Tc-C_804hdE

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

[divider] [/divider] Resources/Tasks to Support Your Child at Home:

  • Give your child a set number of objects.  Give them a ten number to subtract from the total number of objects.  Encourage them to group and subtract by tens until they find the difference.

 

  • Online Video: 10 More or 10 Less (use as a prerequisite for subtracting by ten to help with the understanding of subtracting by multiples of 10)