1.CA.1

Demonstrate fluency with addition facts and the corresponding subtraction facts within 20. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a 10 (e.g., 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 – 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13). Model the role of 0 and the equal sign in addition and subtraction using objects or drawings. (E)

Example Problems
The distribution of final exam scores in a large statistics course was approximately normal with mean points and standard deviation points. Students with scores in the top 15% earned an A.

What is the
minimum score to earn an A?
Round to the nearest whole number.
The distribution of weekly commuting distances among employees at a company was approximately normal with mean and standard deviation . Employees in the top 10% of weekly commuting distances receive an additional travel stipend.

What is the
minimum weekly commuting distance to receive the stipend?
Round to the nearest mile.
The distribution of battery life for a new set of laptops was approximately normal with mean and standard deviation . Laptops with battery life in the top 20% receive a "Pro" label.

What is the minimum battery life for a laptop to receive the
"Pro" label?
Round to the nearest tenth of an hour.
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