diff --git a/keisan.rb b/keisan.rb
new file mode 100755
index 0000000..4ca06cc
--- /dev/null
+++ b/keisan.rb
@@ -0,0 +1,8 @@
+#!/usr/bin/env ruby
+# -*- coding:utf-8 -*-
+loop do
+  print "式(qで終了) >"
+  s = gets&.chomp
+  break if s == "q"
+  puts eval(s)
+end
diff --git a/keisan2.rb b/keisan2.rb
new file mode 100755
index 0000000..5cdf511
--- /dev/null
+++ b/keisan2.rb
@@ -0,0 +1,12 @@
+#!/usr/bin/env ruby
+# -*- coding:utf-8 -*-
+s=""
+loop do
+  c=STDIN.read(1)
+  exit if c=="q"
+  if c=="\n"
+    p eval(s); s=""
+  else
+    s<<c
+  end
+end