Show:
Mental Addition
Mental Subtraction
Mental Addition to 100
Rounding
Front End Estimation
100

Create a number bond. 

34 + 57


34 + 57 = 

34 + 60 = 

34 + 60 = 94

94 - 3 = 91

34 + 57 = 91 

100

Create a number bond 

87 - 37 = 

87 - 37 = 

87 - 40 = 

87 - 40 = 47

47 + 3 = 50 

87-37 = 50

100

Create a number bond. 

Find 86 + 95 

86 + 95 = 

86+ 100 = 

86+100 = 186

186- 5 = 181

86 + 95 = 181 

100

Round 287 to the nearest hundred 

300

100

What is the leading digit in the number 438?

4

200

Create a number bond. 

35 + 57 = 

35 + 57 = 

35 + 60 =

35+ 60 = 95

95 - 3 = 92

35 + 57 = 92

200

Create a number bond.

65 - 47 = 

65 - 47 = 

65 - 50 =

65 - 50 = 15

15 + 3 = 18 

65 - 47 = 18

200

Create a number bond. 

75 +  98 

75 + 98 =

75 + 100 

75 + 100 = 175

175- 2 = 173

75 + 98 = 173


200

Round 908 to the nearest hundred.

900

200
What is the leading digit in the number 9,543?

9

300

Create a number bond.

46 + 47 = 

46 + 47 =

46 + 50 =

46 + 50 = 96

96 - 3 = 93

46 + 47 = 93


300

Create a number bond. 

73 - 46 = 

73 - 46 = 

73 - 50 =

73 - 50 = 23

23+ 4 = 27

73 - 46 =27 

300

Create a number bond. 

63 + 99 = 

63 + 99 = 

63 + 100 =

63 + 100 = 163

163 - 1 = 162

63 + 99 = 162

300

Round 1,154 to the nearest ten.

1,150

300

Find the sum. Then use front-end estimation to check that your answer is reasonable. 

Find 520 + 479 

520 + 479

500 + 400 = 900 

the estimated sum is 900

the answer IS reasonable

400

Create a number bond. 

28 + 36 = 

28 + 36 =

28 + 40 =

28 + 40 = 68

68 - 4 = 64

28 + 36 = 64

400

Create a number bond. 

95- 29 = 

95 - 29 = 

95 - 30 = 

95 - 30 = 65

65 + 1 = 66

95 - 29 = 66

400

Create a number bond for both numbers. 

92 + 96 = 


92 + 96 = 

100 +100 = 

100 + 100 = 200

200 - 8 - 4 = 188 

92 + 96 = 188 

400

Round 1,387 to the nearest hundred

1,400

400

Find the difference. Then use front end estimation to check that your answer is reasonable. 

514 - 135 = 

514 - 135 = 

500 - 100 - 400

the estimated difference is 400. 

the answer IS reasonable.

500

Create a number bond.

66 + 27 = 

66 +27 = 

66 + 30 =

66 + 30 = 96

96 - 3 = 93

66 + 27 = 93

500

Create a number bond. 

82 - 67 = 

82 - 67 = 

82 - 70 = 

82 -70 = 12

12 + 3 = 15

82 - 67 = 15

500

Create a number bond for both numbers.

93 + 99

93 + 99 = 

100 + 100 =

100+ 100 = 200

200 - 7 - 1 = 192

93 + 99 = 192

500

Round 5,937 to the nearest ten.

5,940

500

Joele walks 472 meters. 

Ronald walks 394 meters.

Find the total distance they walk. 

472 + 394 = 

400 + 300 = 700 meters

The estimated distance is 700 meters.

The answer IS reasonable.