Five shell scripts 100 cases

Write 99 multiplication table
[root @ CentOS-1-7-30-LAMP scripts] # CAT chengfabiao.sh
#! / Bin / bash

for((i=1;i<10;i++))
do
for((j=1;j<=i;j++))
do
echo -n "$i $j = $(($i$j))"
echo -n " "

DONE
echo ""
DONE
summarized for use nested loop; and a digital operation using the echo command symbols.