2nd grade math facts: Addition and Subtraction website called XtraMath tracks and reinforces learning.
A math advent calendar for kids with 25 true or false questions from my friend MathPlus.
Best educational math, science, STEM toy gift guide.
NerdMathMom has great ideas for introducing fractions to kids starting as toddlers to help kids get an intuitive sense for basic fractions which comes in handy in elementary school and sets them up for STEM success.
Math is fun through rock and roll math songs from KlapLab. They also have songs for science and grammar.