The crisp new dollar bill that I have just taken from my wallet bears the serial number 24598176. It’s easy to tell that the number is exactly divisible by 2 but not by 5. Is it divisible by 3? by 4?

It’s easy to tell if a given whole number is divisible by 2. Just check whether the last digit is even. There are also simple rules to determine whether a number is ...

Randomly scramble the digits 0, 1, 2, 3, 4, 5 and 6 to form a seven-digit number (or a six-digit number if the leading digit is 0). Rank the following events in order ...

Examples: (1) 475 is divisible by 25 but not by 125. (2) 465 is divisible by 5 but not by a higher power of 5. As 4 + 6 + 5 = 15, it is divisible by 3 though. (3) To check for divisibility of ...

The Mathematics Teacher (MT), an official journal of the National Council of Teachers of Mathematics, is devoted to improving mathematics instruction from grade 8-14 and supporting teacher education ...

After multiplication, it is time to learn certain divisibility rules to ease our calculations. The basic rules for divisibility by 2, 3, 5, 9, 11 are fairly well known. So now we are going to learn ...

A curious query from a class 5 student about divisibility rule 8 in mathematics led to this government primary school teacher SursinhParmar to invent new divisibility rule 8 in maths. Representative ...