The test, written by members of the council's education department, helps teachers to assess children's ability with numbers.
This can then be used to track progress once pupils have received additional support with mathematical skills.
The test will now be used to measure the development of all pupils across the country who receive help through the Government's Every Child Counts strategy.
This provides additional support for Year 2 primary pupils who have fallen behind in maths. It also offers training for teachers so that they can help pupils who are struggling to develop numeracy skills.
In September, more than 600 copies of the Sandwell Early Numeracy Test will be sent to schools across the country to help them chart pupils' progress.
Ian Jones, Sandwell council cabinet member for children and young people, welcomed the decision and said he hoped it would have a positive impact on children's learning.