diff --git a/def.rb b/def.rb
new file mode 100644
index 0000000..84bd62d
--- /dev/null
+++ b/def.rb
@@ -0,0 +1,69 @@
+#!/uar/bin/env ruby
+# -*- coding: utf-8 -*-
+
+def kakunin(x)
+  printf("%s数を入力してね!\n",x)
+  kazu = gets.to_i
+end
+def kakezan(x,y)
+  x*y
+end
+
+def warizan(x,y)
+  x/y
+end
+
+def tasizan(x,y)
+  x+y
+end
+
+def hikizan(x,y)
+  x-y
+end
+
+def comment
+  puts"もう一度入力してね"
+end
+
+while true
+  
+  print"かけ算、割り算、足し算、引き算のうちどれかを選んでね!\n"
+  puts"1.かけ算"
+  puts"2.割り算"
+  puts"3.足し算"
+  puts"4.引き算"
+  puts"5.終わる"
+
+  go=gets.to_i
+  
+  if go==1
+    x = kakunin("かけられる")
+    y = kakunin("かける")
+    printf("答えは%dだよ!\n",kakezan(x,y))
+    redo
+
+  elsif go==2
+    x = kakunin("割られる")
+    y = kakunin("割る")
+    printf("答えは%dだよ!\n",warizan(x,y))
+    redo
+    
+  elsif go==3
+    x = kakunin("足される")
+    y = kakunin("足す")
+    printf("答えは%dだよ!\n",tasizan(x,y))
+    redo
+
+  elsif go==4
+    x = kakunin("引かれる")
+    y = kakunin("引く")
+    printf("答えは%dだよ!\n",hikizan(x,y))
+    redo
+    
+  elsif go==5
+    break
+
+  else
+    comment
+  end
+end
diff --git a/keisan.rb b/keisan.rb
new file mode 100644
index 0000000..78ab650
--- /dev/null
+++ b/keisan.rb
@@ -0,0 +1,12 @@
+#!/usr/bin/env ruby
+# -*- coding: utf-8 -*-
+
+def keisan(x)
+  a = x*2
+  b = 1
+  c = a + b
+end
+
+puts "数値を入れてください。計算した結果を表示します。"
+y = gets.to_i
+printf("%d\n",keisan(y))
diff --git a/koyakusu.rb b/koyakusu.rb
new file mode 100644
index 0000000..eed570e
--- /dev/null
+++ b/koyakusu.rb
@@ -0,0 +1,47 @@
+#!/usr/bin/env ruby
+#-*- coding:utf-8 -*-
+
+i = 1
+a = 1
+yakusu1=[]
+yakusu2=[]
+koyakusu = []
+
+puts"最大公約数を出します"
+puts"1つ目の数字を入力してください"
+suzi1 = gets.to_i
+puts"2つ目の数字を入力してください"
+suzi2 = gets.to_i
+
+while i <= suzi1
+  x = suzi1 % i
+  if x == 0
+    yakusu1<< i
+  end
+  i +=1
+end
+
+while a <= suzi2
+  y = suzi2 % a
+  if y == 0
+    yakusu2 << a
+  end
+  a +=1
+end
+
+i = 0
+
+while i != yakusu1.length
+  yakusu2.each do |n|
+    if yakusu1[i] == n
+      koyakusu << n
+    end
+  end
+  i +=1
+end
+
+if koyakusu.reverse[0] != nil
+  printf("%dと%dの最大公約数は%dです\n",suzi1,suzi2,koyakusu.reverse[0])
+else
+  printf("%dと%dに公約数はありません\n",suzi1,suzi2)
+end
diff --git a/koyakusu_fix.rb b/koyakusu_fix.rb
new file mode 100644
index 0000000..84892fe
--- /dev/null
+++ b/koyakusu_fix.rb
@@ -0,0 +1,45 @@
+#! /usr/bin/env ruby
+#-*- coding:utf-8 -*-
+
+def yakusu(x)
+  i = 1
+  yaku =[]
+  while i <= x
+    y = x % i
+    if y == 0
+      yaku << i
+    end
+    i += 1
+  end
+  return yaku
+end
+
+def koyaku(x,y)
+  a = 0
+  koyakusu = []
+  while a != x.length
+    y.each do |n|
+    if x[a] == n
+      koyakusu << n
+    end
+  end
+  a += 1
+  end
+  return koyakusu
+end
+
+puts"最大公約数を出します"
+puts"1つ目の数字を入力してください"
+suzi1 = gets.to_i
+puts"2つ目の数字を入力してください"
+suzi2 = gets.to_i
+
+yakusu1 = yakusu(suzi1)
+yakusu2 = yakusu(suzi2)
+koyakusu = koyaku(yakusu1,yakusu2)
+
+if koyakusu.reverse[0] != nil
+   printf("%dと%dの最大公約数は%dです\n",suzi1,suzi2,koyakusu.reverse[0])
+else
+  printf("%dと%dに公約数はありません\n",suzi1,suzi2)
+end
diff --git a/nibai.rb b/nibai.rb
new file mode 100644
index 0000000..0afd6e7
--- /dev/null
+++ b/nibai.rb
@@ -0,0 +1,15 @@
+#!/usr/bin/env ruby
+# -*- coding: utf-8 -*-
+
+def bai(x)
+x*2
+end
+
+puts"数値を入れてね。2倍にするよ"
+x= gets.chomp.to_i
+
+printf("%dの2倍は%d\n",x,bai(x))
+
+
+  
+  
diff --git a/shikaku.rb b/shikaku.rb
new file mode 100644
index 0000000..a3a1cb2
--- /dev/null
+++ b/shikaku.rb
@@ -0,0 +1,17 @@
+#!/usr/bin/env ruby
+# -*- coding:utf-8 -*-
+
+def shikaku(tate,yoko)
+  if tate < 0 || yoko <0
+    return nil
+  end
+  return tate*yoko
+end
+
+puts "四角形の面積を計算します。"
+print"縦の長さを入力:"
+tate = gets.to_i
+print"横の長さを入力:"
+yoko = gets.to_i
+printf("この四角形の面積は%dです。\n",shikaku(tate,yoko))
+  
diff --git a/tasizan.rb b/tasizan.rb
new file mode 100644
index 0000000..a5b0156
--- /dev/null
+++ b/tasizan.rb
@@ -0,0 +1,57 @@
+#!/uar/bin/env ruby
+# -*- coding: utf-8 -*-
+while true
+
+print"かけ算、割り算、足し算、引き算のうちどれかを選んでね!\n"
+puts"1.かけ算"
+puts"2.割り算"
+puts"3.足し算"
+puts"4.引き算"
+puts"5.終わり"  
+
+
+  print"やりたい物のすうじをいれてね!を入れてね\n"
+  go=gets.chomp.to_i
+
+  if go==1
+    print"掛けられるを入力してね。\n"
+    k=gets.to_i
+    print"掛ける数を入力してね。\n"
+    kake=gets.to_i
+    answer=k*kake
+    printf("答えは%fだよ!\n",answer)
+    redo
+
+  elsif go==2
+    print"割られるを入力してね!\n"
+    w=gets.to_i
+    print"わるかずをいれてね!"
+    wari=gets.to_i
+    kota=w/wari
+    printf("答えは%fだよ!\n",kota)
+    redo
+    
+  elsif go==3
+    print"足される数入力してね!\n"
+    t=gets.to_i
+    print"足す数を入れて\n"
+    tasu=gets.to_i
+    ko=t+tasu
+    printf("答えは%fだよ!\n",ko)
+    redo
+
+  elsif go==4
+    print"引かれるを入力してね!\n"
+    h=gets.to_i
+    print"引く数を入れて\n"
+    hiku=gets.to_i
+    k=h-hiku
+    printf("答えは%fだよ!\n",k)
+    redo
+
+ elsif go==5
+    break
+
+  end
+end
+