Here, You should obey the Rules!
Now,the Rules is on the screen!
Check the Mathematical Symbol,
Get the units digit of result from two close numbers by the Mathematical Symbol。
The rules are below the symbol. If the units digit of result is in the rules , that two close numbers go together!
e.g.
rules : 2 3 4 7 0
+
5 + 2 = 7 √ —— 7
2 + 3 = 5 X
-
5 - 2 = 3 √ ——5 + 2 = 7 ————7
3 - 2 = 1 X
X
5 ( < 30000) X 2 (<10) = 10 √ ————10
3 X 2 = 6 X
÷
5 ( < 30000) ÷ 2 (<10) = 2 √—— 5 X 2 = 10 ———10
3 ÷ 2 = 1 X