diff --git a/number/all.mjs b/number/all.mjs
new file mode 100644
index 0000000..21a270a
--- /dev/null
+++ b/number/all.mjs
@@ -0,0 +1,2 @@
+export {add} from './add.mjs'
+export {negate} from './negate.mjs'
diff --git a/number/negate.mjs b/number/negate.mjs
new file mode 100644
index 0000000..b9a73cb
--- /dev/null
+++ b/number/negate.mjs
@@ -0,0 +1,3 @@
+export const negate = {
+   number: [[], n => -n]
+}
diff --git a/pocomath.mjs b/pocomath.mjs
index c8f5b18..3c04c11 100644
--- a/pocomath.mjs
+++ b/pocomath.mjs
@@ -1,8 +1,8 @@
 /* Core of pocomath: generates the default instance */
 import PocomathInstance from './PocomathInstance.mjs'
-import * as numberAdd from './number/add.mjs'
+import * as numbers from './number/all.mjs'
 
 const math = new PocomathInstance('math')
-math.install(numberAdd)
+math.install(numbers)
 
 export default math
diff --git a/test/_pocomath.mjs b/test/_pocomath.mjs
index 756a8c0..d1be328 100644
--- a/test/_pocomath.mjs
+++ b/test/_pocomath.mjs
@@ -7,4 +7,8 @@ describe('The default full pocomath instance "math"', () => {
       assert.strictEqual(math.add(1.5, 2.5, 3.5), 7.5)
       assert.strictEqual(math.add(Infinity), Infinity)
    })
+   it('can negate numbers', () => {
+      assert.strictEqual(math.negate(-1), 1)
+      assert.strictEqual(math.add(10, math.negate(3)), 7)
+   })
 })