+ edo -?
Egin ariketa (1)
Asmatu falta den
zenbakia
Egin ariketa (2)
100

-(-2)

+2

100

-5+1

-4

100

-2+X=3

+5

100

+3-2

+1

200

+9-5

+4

200

+9-6

+3

200

+9-X =3

-6

200

-5+3

-2

300

-12-8

-20

300

+13+9

22

300

-X-8 =-20

-12

300

-12-8

-20

400

+15+10

+25

400

-17+17

0

400

-17+X =0

+17

400

+15+11

+26

500

-20+17

-3

500

+23-14

9

500

+23-X =9

-14

500

-27+15

-12