Here are some math websites that can assist your children.
1. Is your child in first grade? This is a collection of 1st grade geometry worksheets.
https://www.thoughtco.com/1st-grade-geometry-worksheets-2312322
2. I have found this website to be the simplest way to explain ratios to kids.
https://www.mathsisfun.com/definitions/ratio.html
3. Absolute Value explained:
https://www.purplemath.com/modules/absolute.htm
4. Rounding worksheet anyone?https://www.homeschoolmath.net/worksheets/rounding.php
5. Mean, Median, Mode, and Range Explained:
https://www.purplemath.com/modules/meanmode.htm