diff --git a/doc/fluid/design/dist_train/distributed_lookup_table_design.md b/doc/fluid/design/dist_train/distributed_lookup_table_design.md
index 4da8b603e41ec45361196c5ea1e9283c112bb728..e289b1ba6e1e1a582a53c529b58f9cd83506e3c2 100644
--- a/doc/fluid/design/dist_train/distributed_lookup_table_design.md
+++ b/doc/fluid/design/dist_train/distributed_lookup_table_design.md
@@ -50,7 +50,7 @@ operator: ![lookup table training](./src/lookup_table_training.png)
  In the condition like the search engine and recommendation system, the number of feature ID may be very large, see 1000000000, then for a lookup table of size 8, the total size of the table is:
 
  ```
- 100000000000 * 8 * 4.0 = 2980.23 GB
+ 100,000,000,000 * 8 * 4.0 = 2980.23 GB
  ```
 
 ### Solution: Distributed storage