Question

Câu 1: Tính

a; 15.80+6-100

b; 2,3.90+88:8

c; 890.21:7-245

Câu 2: Tính nhanh

a; 99+98+97+......+3+2+1

b; 23.(99+2)+23.(1+98)

Answer 1

1>

a) 15.80+6-100

= 1200+6-100

= 1206-100

= 1106

b)2,3.90+88:8

= 270+11

=281

c)890.21:7-245

=18690:7-245

=2670-245

=2425

Answer 2

Sai đề rồi bạn j ơi

Answer 3

Câu 1: a) 15.80+6-100

=1200+6-100=1106

b) 2,3.90+88:8

=207+11=218

c) 890.21:7-245

= 2670-245=2425

Answer 4

Câu 1 : Tính

a;15.80+6-100=1200+6-100=1206-100=1106

b;2,3.90+88:8=207+88:8=207+11=218

c;890.21:7-245=18690:7-245=2670-245=2425

Câu 2 : Tính nhanh

a;99+98+97+......+3+2+1

=(99+1) x <(99-1):1+1> : 2

=100 x 99:2

=4950

b;23.(99+2)+23.(1+98)

=23.(99+2+1+98)

=23.200

=4600

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