bai 1 : Tim hieu cua hai so, biet rang so lon them 735 don vi va so ben them 449 don vi thi duoc hieu moi la 2000.

Bai 2 : Khi thuc hien phep tru hai so, mot ban da so y viet sai nhu sau : o so bi tru co hai chu socuoi cung la 35 da viet thanh 53 nen phep tru sai co ket qua la 1234. Tim hieu dung cu ahia so do.

Bai 3 : TIm mot so biet rang so do cong voi so lon nhat co ba chu so khac nhau roi cong tiep voi so be nhat co bon chu so khac nhau thi duoc so be nhat co nam chu so.

Bai 4 ; Cho ba chu so tu nhieu A ; B ; C. Biet rang tong cua A va B la 492 ; tongg cua B va C la 936 ; tong cua C va A la 714. Tim ba so do.

Bai 5 : HAi kho chu atat ca 2500 tan thoc. Sau khi lay ra o moi kho so tan thoc nhu sau. thi kho thu nhat con 800 tan va kho thu hai con 500 tan. Hoi luc dau moi kho chua bao nhieu tan thoc?

1.tim so bi chia trong phep chia cho 12 co thuong la 35 va so du la so le co 2chu so

2.hieu cua so lon nhat co 4 chu so khac nhau va so nho nhat co 4 chu sola bao nhieu

3.mot hinh chu nhat co chieu dai gap ruoi chieu rong. Neu moi chieu tang them 1m thi duoc hinh chu nhat moi co dien tich tang them 26m2. Tinh chu vi hinh chu nhat

4.trung binh cong cua 2 phan so bang 5/12. Phan so thu nhat hon phan so thu hai 1/6. Tim phan so thu nhat

5.tim y biet (5/7 - y) nhan 4/5 =7/10 + 1/2

6.hieu 2 so =1/3 so be.Tong 2 so la 63. Tim so be