two? - if it's even. (2,4,6,8·.
)
ten? - if it ends in zero
(10,20,30,40·.)
five? - if it ends in five or zero
(5,10,15,20·.)
four?- if you halve the number and the
answer is even (4, 8, 12, 16· `
three? - if you add the digits of
the number together and the answer is divisible by three (111 :
1+1+1 = 3)
