Rounding to the Nearest 10's
25
30
56+32=?
60+30=90
38-34=?
40-30=10
68 x 31=?
Actual= 68x31 = 2108
Estimated = 70x30 = 2100
Difference = 2108-2100 = 8
83
80
78+82=?
80+80=160
54-31=?
50-30=20
33 x 87=?
Actual = 33x87 = 2871
Estimated = 30x90 = 2700
Difference = 2871 - 2700 = 171
98
100
69+89=?
70+90=160
96-61=?
100-60= 40
45 x 76=?
Actual = 45x76 = 3420
Estimated = 50x80 = 4000
Difference = 4000-3420 = 580