Rounding to the nearest 10
Round 18 to the nearest 10
20
Estimate 12 + 15
10-10=0
Round 24 to the nearest 10
20
Estimate 25+15
30+20=50
Estimate 25-14
30-10=20
Round 46 to the nearest 10
50
Estimate 66+21
70+20=90
Estimate 58-43
60-40=20
Round 78 to the nearest 10
90+10=100
Estimate 88-33
90-30=60
Round 93 to the nearest 10
90
Estimate 98+67
100+70=170
Estimate 99-56
100-60=40