1.	Estimate. Round to the nearest ten.
		A.	80 − 30 = 50	B.	70 − 30 = 40
		C.	70 − 40 = 30	D.	80 − 40 = 40
		Hint
	2.	Estimate. Round to the nearest ten.
		A.	90 − 20 = 70	B.	100 − 30 = 70
		C.	100 − 20 = 80	D.	90 − 30 = 60
		Hint
	3.	Estimate. Round to the nearest hundred.
		A.	500 − 200 = 300	B.	600 − 300 = 300
		C.	530 − 300 = 230	D.	500 − 300 = 200
		Hint
	4.	Estimate. Round to the nearest hundred.
		A.	480 − 130 = 350	B.	480 − 130 = 350
		C.	500 − 100 = 400	D.	400 − 100 = 300
		Hint
	5.	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 420 or 430.	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 400 or 500.
		Hint