# Number - Harder substitution

**Here's the Doctor TV tutorial and worksheet on 'Harder substitution'. To work on them now, click on the image to download the worksheet, then click the 'Play' button on the video to watch one of Maths Doctor's teachers explaining this topic. The completed worksheet can be handed to a maths teacher or parent for assessment.**

To use these resources in the future in the classroom, library, or at home, download and print the worksheet. Students then just scan the worksheet's QR (Quick Response) code with a smartphone that has a QR app, or type the worksheet URL into a web browser. Up pops the video to help complete the maths exercise.