Question 1: Calculate 245 - 138 using exchanging methods.

Answer: 107

Question 2: Subtract 368 - 149 by exchanging digits where necessary.

Answer: 219

Question 3: What is 453 - 276? Show your working involving exchanging.

Answer: 177

Question 4: Using exchanging, find the difference between 512 and 394.

Answer: 118

Question 5: Construct the subtraction 427 - 285 on the grid, showing exchanging steps.

Answer: 142

Question 6: Explain the exchanging process in subtracting 364 - 198. Why is exchanging necessary?

Answer: Exchanging is necessary when the digit in the top number is smaller than the digit being subtracted, requiring us to borrow from the next place value to perform the subtraction.

Question 7: Subtract 719 - 436. Show all exchanging steps clearly.

Answer: 283

Question 8: Identify and correct the mistake in this exchange subtraction: 602 - 397 = 215.

Answer: The correct answer is 205, not 215. The mistake was in the borrowing process during subtraction.

Question 9: A shop has 483 pencils. If 295 are sold, how many are left? Use exchanging to find the answer.

Answer: 188

Question 10: Plot the graph of y = 2x for x values from 0 to 5 on the grid.

Answer: 0, 2, 4, 6, 8, 10

Question 11: Construct a triangle with sides 375, 425, and 500 on the grid, showing the steps of measurement.

Answer: Triangle constructed with accurate side lengths.