\(25+20+60+21-30+58-60\)
\(=\left(25+21\right)+\left(20+60\right)-30+58-60\)
\(=46+80-30+58-60\)
\(=126-30+58-60\)
\(=96+58-60\)
\(=154-60=94\)
25+20+60+21-30+58-60=94
nha bn!😀
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70=?
x + 60 = 58 + 25
Tính nhẩm:
60 + 20 + 10 =
40 + 10 + 20 =
30 + 20 + 20 =
60 + 30 =
40 + 30 =
30 + 40 =
Tính nhẩm:
50 + 10 + 20 = 60 + 20 + 10 = 40 + 10 + 10 =
50 + 30 = 60 + 30 = 40 + 20 =
(10 + 20 + 30 + ................. + 900) x (60 x 1 - 60)
Viết số thích hợp vào chỗ chấm:
80 + 20 =… 50 + 50 =… |
30 + 70 =… 90 + 10 =… |
60 + 40 =… 60 + 30 + 10 =… |
|
20+30+50+20+10+70+60=
Tính nhẩm :
a)
b)
| 30 × 2 = ... | 40 × 2 = ... | 10 × 5 = ... |
| 20 × 3 = ... | 50 × 2 = ... | 20 × 4 = ... |
| 60 : 2 = ... | 80 : 2 = ... | 80 : 4 = ... |
| 60 : 3 = ... | 50 : 5 = ... | 90 : 3 = ... |
x + 30 = 20 + 60
