Show:
Estimation: Subtracting
Rounding
Estimation: Addition
Estimation
Estimation: Adding
100

Round to the nearest 10

39 - 22 =

40 - 20= 20

100
Round 56 to the nearest 10
60
100

Using estimation to the nearest 10: 46 + 72 =

50 + 70 = 120

100

Round to the nearest 10

63

60

100

26 + 38 = 

30+40 = 70

200

Round to the nearest 10

51 - 26 =

50-30=20

200
Round 349 to the nearest ten.
350
200

Using estimation to the nearest hundred: 24 + 49 =

20 + 50 = 70

200

Round to the nearest 10

346

340

200

97 + 25 =

100+30=130

300

Round to the nearest 10

81 - 48 = 

80 - 50 = 30

300

Round 864 to the nearest hundred.

900

300

Using estimation to the nearest hundred: 120 + 287=

100 + 300 = 400

300

Round to the nearest 10

782

780

300

148 + 41 = 

150+40=190

400

Round to the nearest 10

71 - 26 = 

70-30=40 

400

Round 743 to the nearest 100.

700

400

Using estimation to the nearest hundred: 423 + 513  =

400 + 500 = 900

400

Round to the nearest 100

293

300

400

Round to the nearest 10 

138 + 129 =

140+130= 270

500

Round to the nearest 100

164 - 131 = 

200-100= 100

500

Steven has 555 marbles in his collection. When asked how many he has to the nearest hundred, he should say:__________

600

500

Using estimation to the nearest hundred: 174 + 425 

200 + 400  = 600

500

Round to the nearest 100

2,452

2,500

500

Round to the nearest 100

202 + 345

200 +300 = 500