public default GraphTraversal<S, Double> math(final String expression) {
        this.asAdmin().getGremlinLang().addStep(Symbols.math, expression);
        return this.asAdmin().addStep(new MathStep<>(this.asAdmin(), expression));
    }
Map the {@link Traverser} to a {@link Double} according to the mathematical expression provided in the argument.

@param expression the mathematical expression with variables refering to scope variables.
@return the traversal with the {@link MathStep} added.
@since 3.3.1
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/dsl/graph/GraphTraversal.java