Reflection: Intrinsic Motivation Extending Partners of 10 and 100 - Section 4: 100th Day Activities


Watching students grapple with mathematical reasoning is one of the most exciting things to do as a teacher of mathematics. Today students were faced with the task of counting out and measuring 100 pennies and 100 snap blocks as two of the tasks. They also had to take a 2-digit number and then count base 10 blocks to reach 100. 

I watched the different strategies that the children employed. One group decided to make the 100 snap blocks in a long line, but they put a purple block at every ten so they could easily count 10, 20, 30, 40...   Another group decided that they could make towers of 10 to keep track of how many they had and then they could put the towers together and measure it.

One group was measuring with a tape measure but the tower of 100 was longer than 60 inches. They came and asked me what to do to which I replied, what can you do? Suddenly one of the boys said, I can just move the tape measure every inch. He moved the tape measure and measured each inch using the 59 to 60 portion of the tape measure. I might have told him to mark and move the whole tape measure, but his strategy worked and they were able to find the total in an adequate way. 

With the 2-digit number and the base 10 blocks, one group had the number 22. They picked up 88 blocks but when they counted it was too high. They knew to take away 10 of the blocks to get 72. They did the same thing with 65 and 45 blocks. Suddenly one of the children said, wait, if I want to get to 100 and I just have to go down one 10 because of the extra ones!  YES!! Her partner quickly said well then if I have 79, I don't need 31, I would need 21. 

As teachers we often jump up and try to tell kids what to do, but what we need to do more of is step back and watch. Let them figure it out. They will then be building a more lasting understanding of numbers. 

  Mathematical Reasoning
  Intrinsic Motivation: Mathematical Reasoning
Loading resource...

Extending Partners of 10 and 100

Unit 8: Numbers Have Patterns
Lesson 3 of 14

Objective: SWBAT use their partners of 10 to add numbers to 1,000 in partners of 100

Big Idea: Students know partners of 10. Can you believe that there are partners of 100 and 1,000 too?

  Print Lesson
2 teachers like this lesson
Math, Number Sense and Operations, Algebra, Patterns (Algebra), Place Value, estimate, problem solving, counting
  75 minutes
screen shot 2014 03 02 at 4 01 49 pm
Similar Lessons
Cover Up
1st Grade Math » Counting by Groups
Big Idea: Yesterday we added it up and today we cover it up. Students will work in pairs as they cover random numbers on a number grid and ask their partner to figure out which numbers are Covered Up!
Waitsfield, VT
Environment: Suburban
Thomas Young
Domino Addition: Understanding the Part/Part/Whole Relationship
2nd Grade Math » Addition and Subtraction Basic Training
Big Idea: The big idea of this lesson is the understanding that addition can be represented as parts of a whole and that we can use addition sentences to represent those parts.
Pepperell, MA
Environment: Rural
Kristen O'Connor
It's As Basic As That
3rd Grade Math » Understanding Multiplication
Big Idea: Students need to master the basic operations. The common core suggests that all four operations are mastered by the end of third grade. This lesson will help determine where to start and what to do next.
Troy, MI
Environment: Suburban
Michelle Marcus
Something went wrong. See details for more info
Nothing to upload