80
| - | 30
| = | ()
|
() | () | () |
20
| + | 40
| = | ()
|
() | () | () |
36+30=
46+50=
56+40=
10+30> +15<20 35+=35-
50+30= 50+50=
6+54=
80-50=
20+7 = 30-20 = 90+9= 60-30 = 24+6 =
51+8= 7+83= 85-5 = 90-70= 45+20=
96-7 = 65+20= 39+8= 4+65=
18+50-7= 80-60+35= 90-(60+30)= 63-(76-70)=
7570 8080-2 32+33+32
5250+2 15-015+0 20+6061+20
20+2060-10 80-4080-50 50-2090-30
70-4050+10 40+5020+70 50+2020+50
70-1070+10 40+4060+30 30+6010+50
70-3030 7869 80-1070-30
□○□=□(岁)
答:爷爷比妈妈大( )岁。