1.	Estimate 5.23 + 3.5 + 6.1 + 7.8 by rounding.
		A.	25	B.	23
		C.	21	D.	20
		Hint
	2.	Estimate 351.62 ÷ 4.9 by rounding.
		A.	97	B.	72
		C.	70	D.	90
		Hint
	3.	Estimate 32.5 + 30.6 + 28.8 + 29.5 by clustering.
		A.	160	B.	130
		C.	80	D.	120
		Hint
	4.	Estimate 196.37 - 75.64 - 112.88.
		A.	20	B.	7.85
		C.	100	D.	10
		Hint
	5.	Estimate 847.52 ÷ 10.89.
		A.	80	B.	77.09
		C.	90	D.	77.83
		Hint