Formative Assessment Task

2nd Grade: Number and Operations in Base Ten

2.NBT.8:Mentally add 10 or 100 to a given number 100–900, and mentally subtract 10 or 100 from a given number 100–900.

Essential Skills and Knowledge (from MSDE Common Core Frameworks)

  • Ability to skip count from a number by 10 and/or 100 including off the decades
  • Ability to model using base ten manipulatives

Materials:

1. Copy the following table.

2. Base Ten Blocks or Digi-Blocks

3. Place Value Dice (10s, 100s) or Digit Cards (see below)

Directions:

1.Copy the desired recording sheet (four variations attached).

2.Students will roll 2-3 place value dice. (Roll 2 if using +/- 10. Roll 3 if using +/- 100.)

3.Students will mentally add the number they rolled.

4.Students will show the number they rolled using Base Ten Blocks or Digi-Blocks.

5.Students will add or subtract 10 or 100 to the number they rolled.

6.Students will say or record the number on the table below or aloud to a partner/teacher.

Considerations:

  • Observe what strategies students use to solve the problem.
  • Students should address the fact that when they count by 10, the ones and hundreds places do not change.
  • They should notice that when we add 100, the ones place and the tens place is the same as the original number rolled.

Note: There are 4 work pages attached below. They are prepared for adding 10, adding 100, subtracting 10, subtracting 100. You are welcome to adapt the pages as desired.


Name2.NBT.8

Draw Number Rolled in Base Ten Blocks
(Use: ☐,|, ) / Number + 10

Name2.NBT.8

Draw Number Rolled in Base Ten Blocks
(Use: ☐,|, ) / Number + 100

Name2.NBT.8

Draw Number Rolled in Base Ten Blocks
(Use: ☐,|, ) / Number - 10

Name2.NBT.8

Draw Number Rolled in Base Ten Blocks
(Use: ☐,|, ) / Number - 100
10 / 20 / 30
40 / 50 / 60
70 / 80 / 90
100 / 200 / 300
400 / 500 / 600
700 / 800 / 900
1 / 2 / 3
4 / 5 / 6
7 / 8 / 9


Teacher notes:
Not yet: Student shows evidence of misunderstanding, incorrect concept or procedure / Got It: Student essentially understands the target concept.
NEEDS IMPROVEMENT
(N) / WITH ASSISTANCE
(W) / INDEPENDENT
(I)
0 Unsatisfactory:
Little Accomplishment
The task is attempted and some mathematical effort is made. There may be fragments of accomplishment but little or no success. Further teaching is required. / 1 Marginal:
Partial Accomplishment
Part of the task is accomplished, but there is lack of evidence of understanding or evidence of not understanding. Further teaching is required. / 2 Proficient:
Substantial Accomplishment
Student could work to full accomplishment with minimal feedback from teacher. Errors are minor. Teacher is confident that understanding is adequate to accomplish the objective with minimal assistance. / 3 Excellent:
Full Accomplishment
Strategy and execution meet the content, process, and qualitative demands of the task or concept. Student can communicate ideas. May have minor errors that do not impact the mathematics.
Adapted from Van de Walle, J. (2004) Elementary and Middle School Mathematics: Teaching Developmentally. Boston: Pearson Education, 65

 Elementary Mathematics Office • Howard County Public School System • 2013-2014