Mental arithmetic becomes much harder as the numbers become bigger, partly because it is much harder to hold a 5 or 6-digit number ‘in your head’ whilst working with it. We have a great selection of on-screen activities which give unlimited practice, are computer marked and also have printable certificates available for high scores. They are arranged in the following categories:

• Counting on: Might sound easy, but counting on in hundreds using 4-digit numbers can prove tricky, and there are always timed challenges for the most able.

• Comparing large numbers: Working with 6-digit numbers, activities include finding the largest number, comparing numbers and finding multiples of 10,000 more or less than large numbers.

• Negative numbers: Finding more than or less than, using negative numbers.

• Rounding numbers: Rounding 6-digit numbers to the nearest 10,000 or 100,000, including timed challenges.