It is important stress not to move your child too quickly through the series unless they are coping well at each point. It is better to spend time focusing on the beginning stages of the ten frame work than rushing through with your child writing the correct answers in later books but having no idea what the numbers all mean. Once your child knows and understands early number the rest will fall into place.
My child is in gr 2 and struggling with understanding numbers. I want my child to know her addition and subtraction number facts fluently by the end of the year.
Firstly establish your child with the ten frame activities (see the ten frames questions). These are crucial in understanding number without which your child cannot memorize number facts efficiently.
Then move your child through some of the Let’s Go! ebooks. As your child is older, he/she could handle starting with Let’s Go! eBook 4, moving onto the Ten Minutes a Day 1: 2 & 3 Addition and Subtraction eBooks, completing one page a day (or however many it takes to get to the level you require).
After that, why not extend her further onto the Ten Minutes a Day 2: eBooks 1 &2 Multiplication and Division. Your child will be fluent in number facts (times tables) and ahead of the rest!