After Saxon Math 7/6, your child should do Saxon Math 8/7. If they completed Saxon Math 8/7 successfully, they are ready to move on to Algebra 1.
If they had trouble nailing down the concepts of Saxon Math 8/7 (fractions, decimals, percents, ratios, proportions, etc.), they should take Algebra 1/2 before taking Algebra 1. Algebra 1/2 reviews the concepts of Saxon Math 8/7 and then begins a slow introduction to the concepts presented in Algebra 1.