diff --git a/guide/english/algorithms/b-trees/index.md b/guide/english/algorithms/b-trees/index.md
index 8a313218b4..4531ddf250 100644
--- a/guide/english/algorithms/b-trees/index.md
+++ b/guide/english/algorithms/b-trees/index.md
@@ -12,6 +12,7 @@ Properties of B-Tree:
 2) A B-Tree is defined by the term minimum degree ‘t’. The value of t depends upon disk block size.
 3) Every node except root must contain at least t-1 keys. Root may contain minimum 1 key.
 4) All nodes (including root) may contain at most 2t – 1 keys.
+5) Speaking in terms of order n , each node must cantain at minimum ciel(m/2) -1 keys and maximum m-1 keys.
 5) Number of children of a node is equal to the number of keys in it plus 1.
 6) All keys of a node are sorted in increasing order. The child between two keys k1 and k2 contains all keys in range from k1 and k2.
 7) B-Tree grows and shrinks from root which is unlike Binary Search Tree. Binary Search Trees grow downward and also shrink from downward.