The following example shows what a factor tree for the number 24 would look like: For example, the number 28 can be broken down to 2 × 2 × 7, irrespective of which composite factors are used first. Here students clearly represent their findings, such as using a factor tree to show how any number can be built by primes. Such activities stimulate students’ curiosity andĪ method which can be used is known as prime factorisation. Then moving to pictorial representations for example, square and triangle numbers loan themselves nicely to diagrams and prime factorisation can be developed using factor trees (see below).Įngage students in number theory activities which involve: Beginning with opportunities for students to 'make' numbers and identify prime factors, square numbers and triangle numbers using counters or blocks and discuss what makes a number a prime number, a square number or a triangle number. In introducing this concept, it is recommended to consider Jerome Bruner's 'Concrete, Pictorial, Abstract' model to structure instruction. the term product which denotes multiplication.prime numbers are numbers with only two factors, one and itself.įor example, the number 13 only has the factors 1 and 13.composite numbers are numbers that have more than 2 factors. For example, 16 has the factors, 1, 2, 4, 8, 16.They identify the properties of square and triangular numbers and predict these numbers through pattern recognition. They understand that if a number is divisible by a composite number, then it is also divisible by the prime factors of this number. They represent composite numbers as a product of their prime factors and use this knowledge to demonstrate skills such as cancelling common prime factors.

At this level, students understand that some numbers have special properties and that these properties can be used to solve problems.

List of prime numbers to 100 000