By 2.—A number is divisible by 2 when it is an even number, that is to say when it ends with 0, 2, 4, 6 or 8, as 70,836.
By 3.—A number is divisible by 3 when its residue is zero or is divisible by 3.
By 4.—A number is divisible by 4 when the number formed by the last two figures to the right is divisible by 4; 7528 is divisible by 4 because 28 is divisible by 4.
By 5.—A number is divisible by 5 when it ends with 0 or 5, as 75,270.
By 6.—A number is divisible by 6 when it is divisible by 2 and 3, as 474, because when a number is divisible by several others it is divisible by their product.
By 8.—A number is divisible by 8 when the number formed by the last three figures to the right is divisible by 8; 37104 is divisible by 8 because 104 is divisible by 8.
By 9.—A number is divisible by 9 when its residue is 9 or 0.
By 10.—A number is divisible by 10 when the last figure to the right is 0.
By 100.—A number is divisible by 100 when the last two figures to the right are 00.
By 11.—A number is divisible by 11 when the sum of the figures of even rank subtracted from the sum of the figures of uneven rank (increased by 11 if necessary) is 0 or divisible by 11, as 95832, 3304081.