Round the numbers to the nearest hundred to estimate the answers.
734 + 576: 700 + 600 = 1,300 (example)
673 + 448: __________ + __________ = __________
743 − 553: __________ − __________ = __________
943 − 278: __________ − __________ = __________
3,462 + 763: __________ + __________ = __________