diff --git a/app.js b/app.js
index ad9a93a..4682d4a 100644
--- a/app.js
+++ b/app.js
@@ -1 +1,5 @@
 'use strict';
+const axios = require('axios');
+axios.get('http://www.google.com').then(res => {
+    console.log(res);
+})
\ No newline at end of file
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..cb17ec7
--- /dev/null
+++ b/package.json
@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "axios": "^1.4.0"
+  }
+}
diff --git a/sum-app/app.js b/sum-app/app.js
new file mode 100644
index 0000000..b46113f
--- /dev/null
+++ b/sum-app/app.js
@@ -0,0 +1,3 @@
+'use strict'
+const s = require('sum');
+console.log(s.multi([1, 2, 3, 4]));
\ No newline at end of file
diff --git a/sum-app/package.json b/sum-app/package.json
new file mode 100644
index 0000000..d2ef639
--- /dev/null
+++ b/sum-app/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "sum-app",
+  "version": "1.0.0",
+  "main": "index.js",
+  "license": "MIT",
+  "dependencies": {
+    "sum": "../sum"
+  }
+}
diff --git a/sum-app/yarn.lock b/sum-app/yarn.lock
new file mode 100644
index 0000000..c2faa2f
--- /dev/null
+++ b/sum-app/yarn.lock
@@ -0,0 +1,6 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+sum@../sum:
+  version "1.0.0"
diff --git a/sum/index.js b/sum/index.js
new file mode 100644
index 0000000..3501032
--- /dev/null
+++ b/sum/index.js
@@ -0,0 +1,27 @@
+'use strict';
+
+/**
+ * 数値の配列を受け取って、その要素の合計を返す関数
+ */
+
+function add(numbers){
+    let result = 0;
+    for (const num of numbers){
+        result = result + num;
+    }
+    return result;
+}
+
+function multi(numbers){
+    let result = 1;
+    for (const num of numbers){
+        result = result * num;
+    }
+    return result;
+}
+
+module.exports = {
+    add: add,
+    multi
+};
+
diff --git a/sum/package.json b/sum/package.json
new file mode 100644
index 0000000..034eb85
--- /dev/null
+++ b/sum/package.json
@@ -0,0 +1,6 @@
+{
+  "name": "sum",
+  "version": "1.0.0",
+  "main": "index.js",
+  "license": "MIT"
+}
diff --git a/yarn.lock b/yarn.lock
new file mode 100644
index 0000000..e0c951d
--- /dev/null
+++ b/yarn.lock
@@ -0,0 +1,60 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+asynckit@^0.4.0:
+  version "0.4.0"
+  resolved "https://registry.yarnpkg.com/asynckit/-/asynckit-0.4.0.tgz#c79ed97f7f34cb8f2ba1bc9790bcc366474b4b79"
+  integrity sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q==
+
+axios@^1.4.0:
+  version "1.4.0"
+  resolved "https://registry.yarnpkg.com/axios/-/axios-1.4.0.tgz#38a7bf1224cd308de271146038b551d725f0be1f"
+  integrity sha512-S4XCWMEmzvo64T9GfvQDOXgYRDJ/wsSZc7Jvdgx5u1sd0JwsuPLqb3SYmusag+edF6ziyMensPVqLTSc1PiSEA==
+  dependencies:
+    follow-redirects "^1.15.0"
+    form-data "^4.0.0"
+    proxy-from-env "^1.1.0"
+
+combined-stream@^1.0.8:
+  version "1.0.8"
+  resolved "https://registry.yarnpkg.com/combined-stream/-/combined-stream-1.0.8.tgz#c3d45a8b34fd730631a110a8a2520682b31d5a7f"
+  integrity sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==
+  dependencies:
+    delayed-stream "~1.0.0"
+
+delayed-stream@~1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/delayed-stream/-/delayed-stream-1.0.0.tgz#df3ae199acadfb7d440aaae0b29e2272b24ec619"
+  integrity sha512-ZySD7Nf91aLB0RxL4KGrKHBXl7Eds1DAmEdcoVawXnLD7SDhpNgtuII2aAkg7a7QS41jxPSZ17p4VdGnMHk3MQ==
+
+follow-redirects@^1.15.0:
+  version "1.15.2"
+  resolved "https://registry.yarnpkg.com/follow-redirects/-/follow-redirects-1.15.2.tgz#b460864144ba63f2681096f274c4e57026da2c13"
+  integrity sha512-VQLG33o04KaQ8uYi2tVNbdrWp1QWxNNea+nmIB4EVM28v0hmP17z7aG1+wAkNzVq4KeXTq3221ye5qTJP91JwA==
+
+form-data@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/form-data/-/form-data-4.0.0.tgz#93919daeaf361ee529584b9b31664dc12c9fa452"
+  integrity sha512-ETEklSGi5t0QMZuiXoA/Q6vcnxcLQP5vdugSpuAyi6SVGi2clPPp+xgEhuMaHC+zGgn31Kd235W35f7Hykkaww==
+  dependencies:
+    asynckit "^0.4.0"
+    combined-stream "^1.0.8"
+    mime-types "^2.1.12"
+
+mime-db@1.52.0:
+  version "1.52.0"
+  resolved "https://registry.yarnpkg.com/mime-db/-/mime-db-1.52.0.tgz#bbabcdc02859f4987301c856e3387ce5ec43bf70"
+  integrity sha512-sPU4uV7dYlvtWJxwwxHD0PuihVNiE7TyAbQ5SWxDCB9mUYvOgroQOwYQQOKPJ8CIbE+1ETVlOoK1UC2nU3gYvg==
+
+mime-types@^2.1.12:
+  version "2.1.35"
+  resolved "https://registry.yarnpkg.com/mime-types/-/mime-types-2.1.35.tgz#381a871b62a734450660ae3deee44813f70d959a"
+  integrity sha512-ZDY+bPm5zTTF+YpCrAU9nK0UgICYPT0QtT1NZWFv4s++TNkcgVaT0g6+4R2uI4MjQjzysHB1zxuWL50hzaeXiw==
+  dependencies:
+    mime-db "1.52.0"
+
+proxy-from-env@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/proxy-from-env/-/proxy-from-env-1.1.0.tgz#e102f16ca355424865755d2c9e8ea4f24d58c3e2"
+  integrity sha512-D+zkORCbA9f1tdWRK0RaCR3GPv50cMxcrz4X8k5LTSUD1Dkw47mKJEZQNunItRTkWwgtaUSo1RVFRIG9ZXiFYg==