AngularCLI and Angular Material (schematics) error: Collection “@angular/material” cannot be resolved

I am trying to use the Angular schemats that are shown on this page.
When I try to use this following command in the terminal at the root of the project ng generate @angular/material:material-nav –name name-of-new-nav, I get the following error in red,

Collection "@angular/material" cannot be resolved. Error: Collection
"@angular/material" cannot be resolved.
at NodeModulesEngineHost._resolveCollectionPath (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular-devkit/schematics/tools/node-module-engine-host.js:88:15)
at NodeModulesEngineHost.createCollectionDescription (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular-devkit/schematics/tools/file-system-engine-host-base.js:106:27)
at SchematicEngine._createCollectionDescription (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular-devkit/schematics/src/engine/engine.js:78:40)
at SchematicEngine.createCollection (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular-devkit/schematics/src/engine/engine.js:71:43)
at Object.getCollection (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular/cli/utilities/schematics.js:28:31)
at GenerateCommand.getOptions (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular/cli/models/schematic-command.js:193:41)
at GenerateCommand. (/Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular/cli/commands/generate.js:38:53)
at Generator.next ()
at /Users/jeremypeters/MEGA/development/learning/angular/material-learn/node_modules/@angular/cli/commands/generate.js:7:71
at new Promise ()

How do I get this to work?

Info: Angular CLI: 6.0.8