standard_description: 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.
problem_activity: A city planner for a neighborhood of Boston is trying to determine if a new park should be built in the neighborhood. She goes around the neighborhood, knocking on doors, asking, “How many children under the age of 7 live in this household?” The data she collected from 28 households is shown in the frequency table below.
| **           # of children under 7 years old in the household          ** | **           Frequency          ** |
|---------------------------------------------------------------------------|------------------------------------|
|                                     0                                     |                 9                  |
|                                     1                                     |                 6                  |
|                                     2                                     |                 8                  |
|                                     3                                     |                 4                  |
|                                     4                                     |                 0                  |
|                                     5                                     |                 1                  |
a.   Create a dot plot to represent the data. Describe your dot plot in words.
b.   What number would you use to represent the center of the data? Explain why you chose that number.
c.   Based on the data, what would you recommend to the city planner about the new park? Does this neighborhood seem like a good place to put the new park? Explain why or why not using the data.


aligns: no