Addition and subtraction within 20 - Related facts - Worksheet

The worksheet focuses on the concept of related facts in the context of addition and subtraction within the number range of 20. It employs bar models to help children visualise and understand the relationship between numbers in a fact family. The exercise starts with a given bar model that illustrates how four different addition and subtraction sentences can be derived from the same set of numbers. For instance, if the bar model shows the numbers 8 and 5 combining to make 13, the corresponding number sentences would be '8 + 5 = 13', '5 + 8 = 13', '13 - 5 = 8', and '13 - 8 = 5'. This example sets the pattern for the children to complete similar bar models and write their own number sentences.

As the children work through the worksheet, they are challenged to fill in missing numbers within the bar models and then construct the four related addition and subtraction sentences for each scenario. The worksheet provides a variety of examples with different numbers, encouraging the children to apply the concept of fact families and understand the inverse relationship between addition and subtraction. The aim is to develop fluency and precision in recognising and using related facts, a fundamental skill in early mathematics education. Additionally, the worksheet includes answers for self-assessment or for teachers to check the children's understanding and accuracy.