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Prime numbers

Prime numbers are the building blocks of the integers and fascinate mathematicians. However, not just mathematicians are intrigued by prime numbers. Author Mark Haddon’s character, Christopher, in the book ‘The …

Multiples and factors

It is easy to get the definitions of ‘multiples’ and ‘factors’ mixed up. Think about the numbers 4 and 12. How would you complete the following sentences using ‘multiple’ and …

Divisibility rules: looking at units

In this and the next step, we’ll be looking at divisibility rules. Here we use properties of numbers to work out whether they are divisible by other numbers without a …

Divisibility rules: multiples of 3

We saw in the last video that the digit in the units column will indicate whether a numbers is a multiple of 2, 5 or 10, but the same method …

Grouping numbers

In this video, Michael and Paula recap the basics of how place value works in a base ten number system. With this fundamental understanding we can now look at how …

The times tables

In this video, Paula discusses the link between even numbers and the two times table. From an early age, students are required to learn their times tables. By the time …

Multiples, factors and primes

Welcome to week two. Last week we looked at how number systems developed and saw that the number system we use today is a ‘place value’ system. In other words …

Summary: number systems

Understanding how other number bases work helps us to appreciate how the base ten system works. Being aware of how numbers work gives students a better feel for number and …

Other number bases: calculations

Challenge Take a look at these two calculations. Both are correct when calculated using a base which is not base ten. The base is different for each calculation. Work out …

Methods for subtraction

Similar to our approaches for addition, in this video Paula and Michael demonstrate the following approaches for subtraction: Column method Chunking Number line When subtracting numbers the column method is …

Other number bases: binary

Earlier in the course we saw how base ten works. It is thought that we use base ten as we have ten digits: eight fingers and two thumbs on our …

How base 10 works

We meet numbers at an early age. It is easy to take numbers for granted. Taking the time to explore exactly what numbers mean, however trivial this may appear, can …

Methods for addition

Many people automatically use a method called column addition when required to add numbers together without the aid of a calculator. The method is efficient and simple to understand. Primary …

Roman numerals

In more recent history, the Roman Empire introduced and spread the use of Roman numerals. This system continues to be used in a limited way to this day: it can …