1. Tim tat ca cac so co 2 chu so sao cho moi so gap 2 lan tich cua no?

2. Tim so nguyen to co 3 chu so biet rang neu viet so do theo thu tu nguoc lai thi ta duc 1 so la lap phuong cua 1 so tu nhien?

3. Tim so tu nhien co 4 chu so biey chu so hang nghin bang chu so hang don vi chu so hang tram bang chu so hang chuc va so do viet duoc duoi dang tich cua 3 so nguyen to lien tiep?

tim 1 so tu nhien o giua 70 va 80 biet rang so do vua co the viet duoc duoi dang tong cua hai so tu nhien lien tiep vua viet duoc duoi dang tong 3 so tu nhien lien tiep     cac ban nho co loi giai chi tiet nhe

Viet cac so do sau duoi dang so do co don vi la m3 :

5cm3; 2306cm3; 0,2cm3; 42dm3; 10,6dm3; 0,9dm3.

tim 1 so tu nhien co 2 chu so biet khi viet themchu so 3 vao dang sau so do thi duoc so lon hon so khi viet themchu so 3 vao dang truoc so do 36 don vi

viet cac so duoi dang so thap phan 

a. co don vi do la kg : 4kg 650g ; 7kg 85g.

b. co don vi do la tan : 3 tan 567kg ; 12tan 27kg.

1)viet day tu nhien tu 1-101 tao thanh so A 

a) A co phai hop so khong

b)A co phai so chinh phuong khong

c)A co the co 35 uoc khong

2)tim so chinh phuong co 4 chu so chu so hang nghin bang chu so hang don vi va so do co the viet duoi dang (5n+4)²

tim mot so tu nhien co 3 chu so biet rang neu viet them chu so 2 vao dang truoc thi duoc so lon hon so do 323 don vi khi viet them chu so 3 vao dang sau so do

tim mot so tu nhien co 3 chu so ,biet neu viet them chu so 8 vao dang truoc dang sau so do thi ta duoc 2 so co 4 chu so nhung so viet dang truoc lon hon so dang sau 5778 don vi

viet cac so do duoi dang so thap phan

a. co don vi do la km : 650m ; 3km 456m ; 7km 35m

b. co don vi do la m : 5m 6dm ; 2m 5cm ; 8m 94mm