diff --git a/bin/hardening.sh b/bin/hardening.sh
index 4a1c770..70d53f5 100755
--- a/bin/hardening.sh
+++ b/bin/hardening.sh
@@ -294,7 +294,7 @@ if [ "$BATCH_MODE" ]; then
     BATCH_SUMMARY+="RUN_CHECKS:${TOTAL_TREATED_CHECKS:-0} "
     BATCH_SUMMARY+="TOTAL_CHECKS_AVAIL:${TOTAL_CHECKS:-0}"
     if [ "$TOTAL_TREATED_CHECKS" != 0 ]; then
-        CONFORMITY_PERCENTAGE=$(bc -l <<<"scale=2; ($PASSED_CHECKS/$TOTAL_TREATED_CHECKS) * 100")
+        CONFORMITY_PERCENTAGE=$(div $(($PASSED_CHECKS * 100)) $TOTAL_TREATED_CHECKS)
         BATCH_SUMMARY+=" CONFORMITY_PERCENTAGE:$(printf "%s" "$CONFORMITY_PERCENTAGE")"
     else
         BATCH_SUMMARY+=" CONFORMITY_PERCENTAGE:N.A" # No check runned, avoid division by 0
@@ -307,8 +307,8 @@ else
     printf "%30s [ %7s ]\n" "Total Passed Checks :" "$PASSED_CHECKS/$TOTAL_TREATED_CHECKS"
     printf "%30s [ %7s ]\n" "Total Failed Checks :" "$FAILED_CHECKS/$TOTAL_TREATED_CHECKS"
 
-    ENABLED_CHECKS_PERCENTAGE=$(bc -l <<<"scale=2; ($TOTAL_TREATED_CHECKS/$TOTAL_CHECKS) * 100")
-    CONFORMITY_PERCENTAGE=$(bc -l <<<"scale=2; ($PASSED_CHECKS/$TOTAL_TREATED_CHECKS) * 100")
+    ENABLED_CHECKS_PERCENTAGE=$(div $(($TOTAL_TREATED_CHECKS * 100)) $TOTAL_CHECKS)
+    CONFORMITY_PERCENTAGE=$(div $(($PASSED_CHECKS * 100)) $TOTAL_TREATED_CHECKS)
     printf "%30s %s %%\n" "Enabled Checks Percentage :" "$ENABLED_CHECKS_PERCENTAGE"
     if [ "$TOTAL_TREATED_CHECKS" != 0 ]; then
         printf "%30s %s %%\n" "Conformity Percentage :" "$CONFORMITY_PERCENTAGE"
diff --git a/debian/control b/debian/control
index e6dcdd1..0358414 100644
--- a/debian/control
+++ b/debian/control
@@ -10,7 +10,7 @@ Vcs-Browser: https://github.com/ovh/debian-cis/
 
 Package: cis-hardening
 Architecture: all
-Depends: ${misc:Depends}, bc, patch
+Depends: ${misc:Depends}, patch
 Description: Suite of configurable scripts to audit or harden a Debian.
  Modular Debian security hardening scripts based on cisecurity.org
  ⟨cisecurity.org⟩ recommendations. We use it at OVH ⟨https://www.ovh.com⟩ to
diff --git a/lib/common.sh b/lib/common.sh
index f351873..151975a 100644
--- a/lib/common.sh
+++ b/lib/common.sh
@@ -112,3 +112,20 @@ sudo_wrapper() {
         crit "Not allowed to \"sudo -n $*\" "
     fi
 }
+
+#
+# Math functions
+#
+
+function div() {
+    local _d=${3:-2}
+    local _n=0000000000
+    _n=${_n:0:$_d}
+    if (($2 == 0)); then
+        echo "N.A"
+        return
+    fi
+    local _r=$(($1$_n / $2))
+    _r=${_r:0:-$_d}.${_r: -$_d}
+    echo $_r
+}
diff --git a/tests/docker/Dockerfile.debian10 b/tests/docker/Dockerfile.debian10
index e45dcfa..a0da842 100644
--- a/tests/docker/Dockerfile.debian10
+++ b/tests/docker/Dockerfile.debian10
@@ -7,7 +7,7 @@ LABEL description="This image is used to run tests"
 
 RUN groupadd -g 500 secaudit && useradd  -u 500 -g 500 -s /bin/bash secaudit && install -m 700 -o secaudit -g secaudit -d /home/secaudit
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y bc openssh-server sudo syslog-ng net-tools auditd
+RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y openssh-server sudo syslog-ng net-tools auditd
 
 COPY --chown=500:500 . /opt/debian-cis/
 
diff --git a/tests/docker/Dockerfile.debian8 b/tests/docker/Dockerfile.debian8
index 44e1e01..f09e938 100644
--- a/tests/docker/Dockerfile.debian8
+++ b/tests/docker/Dockerfile.debian8
@@ -7,7 +7,7 @@ LABEL description="This image is used to run tests"
 
 RUN groupadd -g 500 secaudit && useradd  -u 500 -g 500 -s /bin/bash secaudit && install -m 700 -o secaudit -g secaudit -d /home/secaudit
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y bc openssh-server sudo syslog-ng net-tools auditd
+RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y openssh-server sudo syslog-ng net-tools auditd
 
 COPY --chown=500:500 . /opt/debian-cis/
 
diff --git a/tests/docker/Dockerfile.debian9 b/tests/docker/Dockerfile.debian9
index 9d79ec0..de50a1e 100644
--- a/tests/docker/Dockerfile.debian9
+++ b/tests/docker/Dockerfile.debian9
@@ -7,7 +7,7 @@ LABEL description="This image is used to run tests"
 
 RUN groupadd -g 500 secaudit && useradd  -u 500 -g 500 -s /bin/bash secaudit && install -m 700 -o secaudit -g secaudit -d /home/secaudit
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y bc openssh-server sudo syslog-ng net-tools auditd
+RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y openssh-server sudo syslog-ng net-tools auditd
 
 COPY --chown=500:500 . /opt/debian-cis/