Question 1: Round 4,578 to the nearest 100.

Answer: 4600

Question 2: Round 23,649 to the nearest 100.

Answer: 23600

Question 3: Round 91,234 to the nearest 100.

Answer: 91200

Question 4: Calculate the rounded value of 7,345 to the nearest 100.

Answer: 7300

Question 5: What is 15,789 rounded to the nearest 100?

Answer: 15700

Question 6: Estimate the total of 125,678 and 89,432 by rounding both to the nearest 100.

Answer: 125700 + 89400 ≈ 215100

Question 7: Identify and correct the mistake: 'Rounding 56,349 to the nearest 100 gives 56,300.'

Answer: Incorrect; it should be 56,400 because 349 is closer to 400 than 300.

Question 8: Construct a number between 9,450 and 9,549 that rounds to 9,500.

Answer: Any number from 9,450 to 9,549 inclusive.

Question 9: Round 123,456,789 to the nearest 100.

Answer: 123456800

Question 10: Plot the graph of y=2x on the grid, where x=0 to 10.

Answer: Plot points at (0,0), (1,2), (2,4), ..., (10,20).

Question 11: Construct a triangle with side lengths 245, 300, and 290, then round each side length to the nearest 100 and describe the new triangle.

Answer: Sides rounded to 200, 300, and 300; the new triangle has sides approximately 200, 300, and 300.