+ b
= (а+b) + 
- b
= (а-b) + 
+ 3
= (6+3) +
= 9
= 10
+ 5
= (10+5) +
= 15
= 16 
+ 2
= (2+2) +
= 4
= 5 
+ 3
= (1+3) +
= 4
= 4
= 5 
=
-
=
= 
=
-
=
= 
= 4 -
=
-
=
-
=
=
= 2 
= 10 -
=
-
=
-
=
= 
- 2
= 4
- 2
= (4-2) +
= 2 
= 4 + 1
= 4 +
= 4
)
- 8
= 13
- 8
= (13-8) +
= 5
= 5 
- 5
= 7
- 5
= (7-5) +
= 2
= 2 
- 4
= 6
- 4
= (6-4) +
= 2
= 2 
- 6
= (14-6) +
= 8
+ 7
) - (13
- 9
) = 16 
+ 7
= (12+7) +
= 19
= 20
- 9
= 12
- 9
= (12-9) +
= 3 
= 19
- 3
= (19-3) +
= 16
2ч50мин-160мин=10мин
10148+10т481кг=20т729кг
1082ц+2т=108200кг+2000кг=110200кг
1сут3ч-24ч=3ч
14км-1400м=12км600м
706дм+71м=7060+7100=15660см