问
1+2-(-3)+4-(-5)+6-(-7)+8-(-9)+10=?
1+2-(-3)+4-(-5)+6-(-7)+8-(-9)+10
=1+2+3+4+5+6+7+8+9+10
=(1+10)x5
=11x5
=55
那不就等于从1加到10么
等于55