1.   Estimate. Round to the nearest ten or use compatible numbers.

    A. 100 − 20 = 75 B. 90 − 30 = 50
    C. 50 − 25 = 25 D. 95 − 25 = 70
    Hint

  2.   Estimate. Round to the nearest ten or use compatible numbers.

    A. 75 − 50 = 20 B. 40 − 30 = 10
    C. 100 − 25 = 75 D. 70 − 40 = 30
    Hint

  3.   Estimate. Round to the nearest hundred.

    A. 500 − 300 = 200 B. 600 − 300 = 300
    C. 500 − 200 = 300 D. 530 − 300 = 230
    Hint

  4.   What are the steps you would take to round 428 to the nearest ten?
    A. Look at a number line and see whether 428 is closer to 400 or 500. B. Notice that the first two digits are 4 and 2, and then round to 420.
    C. Notice that the first digit is 4, and then round to 400. D. Look at a number line and see whether 428 is closer to 420 or 430.
    Hint

  5.   Estimate. Round to the nearest hundred.

425 − 298 = ___

    A. 430 − 300 = 130 B. 400 − 300 = 100
    C. 500 − 300 = 200 D. 400 − 200 = 200
    Hint