Toán Lớp 4: Tính bằng cách thuận tiện nhất.
a. 20 x 2021 x 50 b. 2021 x 65 – 2021 x 55
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 4: Tính bằng cách thuận tiện nhất.
a. 20 x 2021 x 50 b. 2021 x 65 – 2021 x 55
Comments ( 2 )
a) 20xx2021xx50
=(20xx50)xx2021
=100xx2021
=202100
b) 2021xx65-2021xx55
=2021xxx(65-55)
=2021xx10
=20210
$\text{a) 20 × 2021 × 50}$
$\text{= (20 × 50) × 2021}$
$\text{= 1000 × 2021}$
$\text{= 2021000}$
$\text{b) 2021 × 65 – 2021 × 55}$
$\text{= 2021 × (65 – 55)}$
$\text{= 2021 × 10}$
$\text{= 20210}$
$\textit{Ha1zzz}$