Show:
Estimation Addition
Addition (with 10s)
Addition (Within Decade)
Addition (Outside Decade)
Addition (Outside Decade)
100

Estimate:

52+16 = 

50+20=70

100

47+30=

77

100

53+6=

59

100

12+9=

21


100

75+8=

83

200

Estimate:

38+27=

40+30=70

200

26+70=

96

200

21+4=

25

200

24+8=

32

200

89+8=

97

300

Estimate:

42+49=

40+50=90

300

40+25=

65

300

35+3=

38

300

37+7=

44

300

56+5=

61

400

Estimate: 

13+67=

10+70=80

400

18+50=

68

400

72+6=

78

400

48+3=

51

400

88+8=

96

500

Estimate:

35+15=

40+20=60

500

19+20=

39

500

91+4=

95

500

57+6=

63

500

79+5=

84