A clever 'Big Maths' technique to easily calculate numbers that add together to equal 1000.
An extension of simple fact families. Understanding how to generate these fact families from simpler ones, is a particularly good strategy to have especially when tackling division problems using the 'chunking' method, when the numbers we are dealing with get bigger! See division of 3 digits by 1 digit for more information.
3 digits + 3 digits
This is a Big Maths term meaning a group of connected mathematical facts. Understanding fact families is really useful, especially when dealing with algebraic questions (where there is a missing number in the question). To illustrate this using a simple example, if you were asked 3 + ? = 10, you could work out the missing number by creating the fact family, ie 10 - 3 = 7 so 7 is the missing number because it fits into the fact family.
2 digits + 2 digits
This is the more formal method of column addition. A firm understanding of place value is essential.
2 digits divided by 1 digit.