For Math and Language Arts we recommend: Singapore Math https://www.singaporemath.com/

My children used the entire Primary Math Series with great success!

You can easily purchase consumable workbooks and reusable Teacher Guides. Additionally, placement testing is available on their website.

I really Love Singapore Math because it teaches the language of Math from the very first lesson.  Concepts such as: a linear visual for equation development is used in contrast to teaching a vertical equation development first and switching to a linear version for algebra.  In other words, students are taught math with an algebra framework from day one so that by the time they reach pre-algebra, the transition is seamless.  Singapore Math is also excellent at teaching critical thinking for word problems.  This also begins very early in the curriculum such as my example of my son and the missing apples inside a bag.  I’m convinced that Singapore Math taught my children to like math.  They each pursued career paths requiring higher math as a result!  With the everchanging world of Technology, a solid grasp of mathematics is critical to future career opportunities and higher salaries to match.