Toán Lớp 7: Tính nhanh:
10 + 20 + … + 100 =?
Leave a reply
Register Now
Login
Lost Password
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Toán Lớp 7: Tính nhanh:
10 + 20 + … + 100 =?
Comments ( 2 )
= 10 + 10 x 2+ … + 10 x 10
= 10(1+ 2+ … + 10)
= 10 x 55
= 550