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Estimate the Sum
Adding
Estimate the Difference
Subtraction
Bonus!
100

4.67+2.9=

8

100

12+6.99=

18.99

100

5.6-2.3=

4

100

12.44-8=

4.44

100

The greek root that means 'life'

bio

200

3.08+24.65=

28

200

18.16+5=

23.16

200

4.22-1.6=

2
200

8.85-2.92=

5.93

200

The greek root that means 'self'

auto

300

14.51+2.18=

17

300

3.53+3.62=

7.15

300

8.02-5.33=

3

300

10.5-7.46=

3.04

300

The greek root that means 'to hear'

aud

400

5.32+17.9=

23

400

11.88+4.44=

16.32

400

20.1-3.43=

17

400
14-8.47=

5.53

400
The greek root that means "to see"

vid, vis

500

9.17+13.9=

23

500

7.59+18.6=

26.19

500

19.08-2.54=

16

500

6.1-2.99=

3.11

500

The greek root that means 'light'

photo