bai 12:Mot vuon co so cay buoi bang 1phan2 cay cam,biet so cay cam bang so chan lon nhat co 3 chu so.Hoivuon do co tat ca bao nhieu cay buoi va cam?

bai 13:tim tich cua so nho nhatco ba chu so khac nhau voi so chan lon nhat co mot chu so.

bai 14:tim mot so,biet rang giam so do di 5 lan sau do them 10 don vi thi duoc so le nho nhat co hai chu so.

bai 15:tim mot so biet rang neu gap so do len 4 lan,duoc bao nhieu lai gap len 6 lan thi duoc 360.

tim mot so co hai chu so,biet rang tich cua hai chu so bang 20 va trong do co mot chu so la 6

bài 1: a) binh nghi ra mot so .Biet rang so lon nhat co hai chu so hon so do la 65.tim so binh da nghi.

b) an nghi ra mot so. biet rang so do be hon so be nhat co ba chu so la 15. tim so an da nghi.

bai 2: tu ba chu so 5, 2, 3 an lap duoc so lon nhat va so be nhat co mat du ba chu so do , roi tinh hieu hai so vua lap duoc . hieu do la bao nhieu ???nhanh len nhe mik dang can rat gap 

tim chieu dai chieu rongcua hinh chu nhat co dien tich la 12 cm nhung co chu vi be nhat biet rang so do chieu dai va so do chieu rong voi don vi do la xang-ti-met

Bai 4 : Hieu hai so la so lon nhat co hai chu so , tim hai so do . Biet rang 1/7 so thu nhat bang 1/4 so thu hai

tim hieu cua so lon nhat co bon chu so va so be nhat co bon chu do ,biet rang tong cac chu so cua moi so do bang 15.

tim mot so tu nhien  co 3 chu so khac nhau be nhat biet rang so do  bang tong tat ca cac so co hai chu so khac nhau lap duoc tu 3 chu so cua so do

tim so lon nhat co 3 chu so biet rang so do chia co 15 duoc thuong la so lon nhat co hai chu so va so du la so du lon nhat co the trong phep chia do.

tim hai so co 2 chu so biet rang tong cua hai so do la 98 neu gep so lon vao ben trai va ben phai cua so be deu duoc cac so co 4 chu so ma hieu cua chung bang 1386 tim hai so do