Diem said that the quotient of 4.2 /5 is about 8 tenths because 4.⅖ is close to 40 tenths/5. Do you agree with Diem’s reasoning? Explain why or why not.

9514 1404 393

  yes, 42/10 is near 40/10

Step-by-step explanation:

(4.2)/5 is (42/10)/5, which is about (40/10)/5, which is 8/10.

I might think of it as (4.2)/5 is about 4/5, which is 8/10.

Diem's reasoning is good, and his estimate of the answer is appropriate.

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)