The test papers include answers intentionally so that parents can have an idea of the answers required.
You can blank out the answers digitally by using an online pdf editing tool.
This is a free online tool for editing pdf. Here's what you need to do.
1. Download the test paper pdf you want to your desktop pc
2. Go to this page http://www.pdfescape.com/open/ and click on "Upload pdf to pdf escape"
3. Choose file to upload or drag and drop file into the box
4. Once your file is uploaded and the pdf editor is open, click on "whiteout"
5. Place your cursor on the screen, hold and drag over the area you wish to blank out, then release
6. After you have finished editing your document, click on the little green icon with two downwards pointing arrows to save and download your edited pdf.
7. You can now let your child practice on the paper