Adjust your work hours
A normal school day is from 9-3, so chances are your primary-aged child will need some help during that time. Instead of trying to juggle emails and fractions, it might be worth setting aside an hour or two to focus solely on your child. Speak to your boss or team to find out if you can adjust your work hours.
Perhaps you could suggest adding on time early in the morning or in the evening when your little one has finished their school work. This will enable you to focus on one thing at a time, rather than trying to multi-task.