Multiplication and division

problem

Times Right

Age

11 to 16

Challenge level

Using the digits 1, 2, 3, 4, 5, 6, 7 and 8, mulitply a two two digit numbers are multiplied to give a four digit number, so that the expression is correct. How many different solutions can you find?
problem

Factorial

Age

14 to 16

Challenge level

How many zeros are there at the end of the number which is the product of first hundred positive integers?
problem

Vedic Sutra - All From 9 and Last From 10

Age

14 to 16

Challenge level

Vedic Sutra is one of many ancient Indian sutras which involves a cross subtraction method. Can you give a good explanation of WHY it works?
problem

Galley Division

Age

14 to 16

Challenge level

Can you explain how Galley Division works?
article
Multiplication Series: Illustrating Number Properties With Arrays

This article for teachers describes how modelling number properties involving multiplication using an array of objects not only allows children to represent their thinking with concrete materials, but it can also assist them in forming useful mental pictures to support memory and reasoning.
article
Difficulties With Division

This article for teachers looks at how teachers can use problems from the NRICH site to help them teach division.
article
2010: A Year of Investigations

This article for teachers suggests ideas for activities built around 10 and 2010.
article
Children's Mathematical Graphics: Understanding the Key Concept

In this article for teachers, Elizabeth Carruthers and Maulfry Worthington explore the differences between 'recording mathematics' and 'representing mathematical thinking'.
article
Place Value as a Building Block for Developing Fluency in the Calculation Process

This article for primary teachers encourages exploration of two fundamental ideas, exchange and 'unitising', which will help children become more fluent when calculating.
article
Let's Get Flexible!

In this article for primary teachers, Ems outlines how we can encourage learners to be flexible in their approach to calculation, and why this is crucial.