a) 25+38+59-5-19-8
=(25-5)+(38-8)+(59-19)
=20+30+40
=90
b)26-12+42-16+89-69
=(26-16)+(42-12)+(89-69)
=10+30+20
=60
a) 25+38+59-5-19-8 b) 26-12+42-16+89-69
= (25-5)+(38-8)+(59-19) = (26-16)+(42-12)+(89-69)
= 20+30+40 = 10+30+20
= 90 = 60
a) 25+38+59-5-19-8
=(25 - 5 ) + (38-8) +(59-19)
= 20 +30 + 40
= 60+40
=100
b) 26-12+42-16+89-69
= (26-16) + (42-12) + (89-69)
= 20+30+20
=50 +20
=70
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=?
Số ?
| Số hạng | 19 | 59 | 49 | 9 |
|---|---|---|---|---|
| Số hạng | 16 | 28 | 22 | 69 |
| Tổng |
cho em hỏi bài tính nhanh lớp 2 này giải như thế nào
79 - 16 + 11 + 10 + 26
20 - 19 + 39 - 38 + 26 - 25 + 10
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
28+27+26+25+24+23+22+21+20+19+18+17+16+15+14+13+12+11+10+9+8+7+6+5+4+3+2+1+=....................................................?
38 x 12=?
17 x 26 =?
59 x 63=?
2+4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40+42+44+46+48=??
nhanh mk tk, đưg quên kb vs mk nha
12+12-23=
26+32-11=
10+37-26=
19+42-10=
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=bn
ai nhanh mk tick cho,nhớ kb với mk nha