Tính nhẩm:
a) 15 cm2 + 20 cm2 = ..................
60 cm2 - 42 cm2 = ..................
20 cm2 + 10 cm2 + 15 cm2 = ..................
b) 12 cm2 x 2 = ..................
40 cm2 : 4 = ..................
50 cm2 - 40 cm2 + 10 cm2 = ..................
10+20+30+40+50+60+70+80+90+100=..................
10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90 +100 + 200 + 300 =
tính nhanh ;
10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90 + 100
tk nhé
Tính nhanh :
\(10+20+30+40+50+60+70+80+90\)
1+1+1+1+1+1+1+1+10+20+30+40+50+60+70+80+90+1=????
giao hoan va chuyen doi : 60-61+50-51+40-41+30-31+20-21+10-11+70
10 + 20 + 30 + 40 + 50 + 60 + 70 + 80 + 90 + 100 = ?
ai nhanh nhất mình tick cho.
Tính:
A=1+2+3+4+5+5+6+7+8+9+10
B=10+20+30+40+50+50+60+70+80+90+100