Tính bằng cách thuận tiện
a. 237 + 357 + 763
d. 2345 + 4257 – 345
b.1987 – 538 – 462
e. 5238 – 476 + 3476
c. 4276 + 2357 + 5724 + 7643
f. 3145 + 2496 + 5347 + 7504 +...
Đọc tiếp
Tính bằng cách thuận tiện
|
a. 237 + 357 + 763 |
d. 2345 + 4257 – 345 |
|
b.1987 – 538 – 462 |
e. 5238 – 476 + 3476 |
|
c. 4276 + 2357 + 5724 + 7643 |
f. 3145 + 2496 + 5347 + 7504 + 465 |
\(a.\) \(237+357+763\)
\(=\left(237+763\right)+357\)
\(=1000+357\)
\(=1357\)
\(b.\) \(1987-538-462\)
\(=1987-\left(538+462\right)\)
\(=1987-1000\)
\(=987\)
\(c.\) \(4276+2357+5724+7643\)
\(=\left(4276+5724\right)+\left(2357+7643\right)\)
\(=10000+10000\)
\(=20000\)
\(d.\) \(2345+4257-345\)
\(=4257+\left(2345-345\right)\)
\(=4257+2000\)
\(=6257\)
\(e.\) \(5238-476+3476\)
\(=5238+\left(3476-476\right)\)
\(=5238+3000\)
\(=8238\)
\(f.\) \(3145+2496+5347+7504+465\)
\(=\left(3145+465\right)+\left(2496+7504\right)+5347\)
\(=3610+10000+5347\)
\(=10000+\left(3610+5347\right)\)
\(=10000+8957\)
\(=18957\)