diff --git a/.travis.yml b/.travis.yml
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,1 +1,90 @@
-language: haskell
+# This file has been generated -- see https://github.com/hvr/multi-ghc-travis
+language: c
+sudo: false
+
+cache:
+  directories:
+    - $HOME/.cabsnap
+    - $HOME/.cabal/packages
+
+before_cache:
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/build-reports.log
+  - rm -fv $HOME/.cabal/packages/hackage.haskell.org/00-index.tar
+
+matrix:
+  include:
+    - env: CABALVER=1.16 GHCVER=7.0.4
+      compiler: ": #GHC 7.0.4"
+      addons: {apt: {packages: [cabal-install-1.16,ghc-7.0.4], sources: [hvr-ghc]}}
+    - env: CABALVER=1.16 GHCVER=7.2.2
+      compiler: ": #GHC 7.2.2"
+      addons: {apt: {packages: [cabal-install-1.16,ghc-7.2.2], sources: [hvr-ghc]}}
+    - env: CABALVER=1.16 GHCVER=7.4.2
+      compiler: ": #GHC 7.4.2"
+      addons: {apt: {packages: [cabal-install-1.16,ghc-7.4.2], sources: [hvr-ghc]}}
+    - env: CABALVER=1.16 GHCVER=7.6.3
+      compiler: ": #GHC 7.6.3"
+      addons: {apt: {packages: [cabal-install-1.16,ghc-7.6.3], sources: [hvr-ghc]}}
+    - env: CABALVER=1.18 GHCVER=7.8.4
+      compiler: ": #GHC 7.8.4"
+      addons: {apt: {packages: [cabal-install-1.18,ghc-7.8.4], sources: [hvr-ghc]}}
+    - env: CABALVER=1.22 GHCVER=7.10.2
+      compiler: ": #GHC 7.10.2"
+      addons: {apt: {packages: [cabal-install-1.22,ghc-7.10.2], sources: [hvr-ghc]}}
+
+before_install:
+ - unset CC
+ - export PATH=/opt/ghc/$GHCVER/bin:/opt/cabal/$CABALVER/bin:$PATH
+
+install:
+ - cabal --version
+ - echo "$(ghc --version) [$(ghc --print-project-git-commit-id 2> /dev/null || echo '?')]"
+ - if [ -f $HOME/.cabal/packages/hackage.haskell.org/00-index.tar.gz ];
+   then
+     zcat $HOME/.cabal/packages/hackage.haskell.org/00-index.tar.gz >
+          $HOME/.cabal/packages/hackage.haskell.org/00-index.tar;
+   fi
+ - travis_retry cabal update -v
+ - sed -i 's/^jobs:/-- jobs:/' ${HOME}/.cabal/config
+ - cabal install --only-dependencies --enable-tests --enable-benchmarks --dry -v > installplan.txt
+ - sed -i -e '1,/^Resolving /d' installplan.txt; cat installplan.txt
+
+# check whether current requested install-plan matches cached package-db snapshot
+ - if diff -u installplan.txt $HOME/.cabsnap/installplan.txt;
+   then
+     echo "cabal build-cache HIT";
+     rm -rfv .ghc;
+     cp -a $HOME/.cabsnap/ghc $HOME/.ghc;
+     cp -a $HOME/.cabsnap/lib $HOME/.cabsnap/share $HOME/.cabsnap/bin $HOME/.cabal/;
+   else
+     echo "cabal build-cache MISS";
+     rm -rf $HOME/.cabsnap;
+     mkdir -p $HOME/.ghc $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin;
+     cabal install --only-dependencies --enable-tests --enable-benchmarks;
+   fi
+ 
+# snapshot package-db on cache miss
+ - if [ ! -d $HOME/.cabsnap ];
+   then
+      echo "snapshotting package-db to build-cache";
+      mkdir $HOME/.cabsnap;
+      cp -a $HOME/.ghc $HOME/.cabsnap/ghc;
+      cp -a $HOME/.cabal/lib $HOME/.cabal/share $HOME/.cabal/bin installplan.txt $HOME/.cabsnap/;
+   fi
+
+# Here starts the actual work to be performed for the package under test;
+# any command which exits with a non-zero exit code causes the build to fail.
+script:
+ - if [ -f configure.ac ]; then autoreconf -i; fi
+ - cabal configure --enable-tests --enable-benchmarks -v2  # -v2 provides useful information for debugging
+ - cabal build   # this builds all libraries and executables (including tests/benchmarks)
+ - cabal test
+ - cabal sdist   # tests that a source-distribution can be generated
+
+# Check that the resulting source distribution can be built & installed.
+# If there are no other `.tar.gz` files in `dist`, this can be even simpler:
+# `cabal install --force-reinstalls dist/*-*.tar.gz`
+ - SRC_TGZ=$(cabal info . | awk '{print $2;exit}').tar.gz &&
+   (cd dist && cabal install --force-reinstalls "$SRC_TGZ")
+
+# EOF
diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,7 @@
+0.1
+-----
+* Added functions `floor`, `ceil`, `trunc`, `modf` and `remainder`
+
 0.0.3
 -----
 * Marked `Numeric.Extras` `Trustworthy`.
diff --git a/Numeric/Extras.hs b/Numeric/Extras.hs
--- a/Numeric/Extras.hs
+++ b/Numeric/Extras.hs
@@ -7,9 +7,20 @@
     ( RealExtras(..)
     ) where
 
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 710
+import Control.Applicative ((<$>), (<*>))
+#endif
+import Control.Arrow ((***))
 import Foreign
 import Foreign.C.Types
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
+import System.IO.Unsafe (unsafeDupablePerformIO)
+#else
+import System.IO.Unsafe (unsafePerformIO)
+#endif
 
+{-# ANN module "HLint: ignore Use camelCase" #-}
+
 class (Storable (C a), RealFloat (C a), RealFloat a) => RealExtras a where
     type C a :: *
     fmod :: a -> a -> a
@@ -18,6 +29,11 @@
     hypot :: a -> a -> a
     cbrt  :: a -> a
     erf   :: a -> a
+    floor :: a -> a
+    ceil  :: a -> a
+    trunc :: a -> a
+    modf  :: a -> (a, a)
+    remainder :: a -> a -> a
 
 instance RealExtras Double where
     type C Double = CDouble
@@ -27,15 +43,31 @@
     hypot = lift2D c_hypot
     cbrt = lift1D c_cbrt
     erf = lift1D c_erf
+    floor = lift1D c_floor
+    ceil  = lift1D c_ceil
+    trunc = lift1D c_trunc
+    modf = lift1D2 c_modf
+    remainder = lift2D c_remainder
 
 lift1D :: (CDouble -> CDouble) -> Double -> Double
 lift1D f a = realToFrac (f (realToFrac a))
 {-# INLINE lift1D #-}
 
+lift1D2 :: (CDouble -> (CDouble, CDouble)) -> Double -> (Double, Double)
+lift1D2 f a = (realToFrac *** realToFrac) (f (realToFrac a))
+{-# INLINE lift1D2 #-}
+
 lift2D :: (CDouble -> CDouble -> CDouble) -> Double -> Double -> Double
 lift2D f a b = realToFrac (f (realToFrac a) (realToFrac b))
 {-# INLINE lift2D #-}
 
+c_modf :: CDouble -> (CDouble, CDouble)
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
+c_modf a = unsafeDupablePerformIO $ alloca $ \i -> (,) <$> c_modf_imp a i <*> peek i
+#else
+c_modf a = unsafePerformIO $ alloca $ \i -> (,) <$> c_modf_imp a i <*> peek i
+#endif
+
 instance RealExtras Float where
     type C Float = CFloat
     fmod = lift2F c_fmodf
@@ -44,39 +76,75 @@
     hypot = lift2F c_hypotf
     cbrt  = lift1F c_cbrtf
     erf   = lift1F c_erff
+    floor = lift1F c_floorf
+    ceil  = lift1F c_ceilf
+    trunc = lift1F c_truncf
+    modf = lift1F2 c_modff
+    remainder = lift2F c_remainderf
 
 lift1F :: (CFloat -> CFloat) -> Float -> Float
 lift1F f a = realToFrac (f (realToFrac a))
 {-# INLINE lift1F #-}
 
+lift1F2 :: (CFloat -> (CFloat, CFloat)) -> Float -> (Float, Float)
+lift1F2 f a = (realToFrac *** realToFrac) (f (realToFrac a))
+{-# INLINE lift1F2 #-}
+
 lift2F :: (CFloat -> CFloat -> CFloat) -> Float -> Float -> Float
 lift2F f a b = realToFrac (f (realToFrac a) (realToFrac b))
 {-# INLINE lift2F #-}
 
-foreign import ccall unsafe "math.h fmod" 
+c_modff :: CFloat -> (CFloat, CFloat)
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 702
+c_modff a = unsafeDupablePerformIO $ alloca $ \i -> (,) <$> c_modff_imp a i <*> peek i
+#else
+c_modff a = unsafePerformIO $ alloca $ \i -> (,) <$> c_modff_imp a i <*> peek i
+#endif
+
+foreign import ccall unsafe "math.h fmod"
     c_fmod :: CDouble -> CDouble -> CDouble
-foreign import ccall unsafe "math.h expm1" 
+foreign import ccall unsafe "math.h expm1"
     c_expm1 :: CDouble -> CDouble
-foreign import ccall unsafe "math.h log1p" 
+foreign import ccall unsafe "math.h log1p"
     c_log1p :: CDouble -> CDouble
-foreign import ccall unsafe "math.h hypot" 
+foreign import ccall unsafe "math.h hypot"
     c_hypot :: CDouble -> CDouble -> CDouble
-foreign import ccall unsafe "math.h cbrt" 
+foreign import ccall unsafe "math.h cbrt"
     c_cbrt :: CDouble -> CDouble
 foreign import ccall unsafe "math.h erf"
     c_erf :: CDouble -> CDouble
+foreign import ccall unsafe "math.h floor"
+    c_floor :: CDouble -> CDouble
+foreign import ccall unsafe "math.h ceil"
+    c_ceil :: CDouble -> CDouble
+foreign import ccall unsafe "math.h trunc"
+    c_trunc :: CDouble -> CDouble
+foreign import ccall unsafe "math.h modf"
+    c_modf_imp :: CDouble -> Ptr CDouble -> IO CDouble
+foreign import ccall unsafe "math.h remainder"
+    c_remainder :: CDouble -> CDouble -> CDouble
 
-foreign import ccall unsafe "math.h fmodf" 
+foreign import ccall unsafe "math.h fmodf"
     c_fmodf :: CFloat -> CFloat -> CFloat
-foreign import ccall unsafe "math.h expm1f" 
+foreign import ccall unsafe "math.h expm1f"
     c_expm1f :: CFloat -> CFloat
-foreign import ccall unsafe "math.h log1pf" 
+foreign import ccall unsafe "math.h log1pf"
     c_log1pf :: CFloat -> CFloat
-foreign import ccall unsafe "math.h hypotf" 
+foreign import ccall unsafe "math.h hypotf"
     c_hypotf :: CFloat -> CFloat -> CFloat
-foreign import ccall unsafe "math.h cbrtf" 
+foreign import ccall unsafe "math.h cbrtf"
     c_cbrtf :: CFloat -> CFloat
 foreign import ccall unsafe "math.h erff"
     c_erff :: CFloat -> CFloat
+foreign import ccall unsafe "math.h floorf"
+    c_floorf :: CFloat -> CFloat
+foreign import ccall unsafe "math.h ceilf"
+    c_ceilf :: CFloat -> CFloat
+foreign import ccall unsafe "math.h truncf"
+    c_truncf :: CFloat -> CFloat
+foreign import ccall unsafe "math.h modff"
+    c_modff_imp :: CFloat -> Ptr CFloat -> IO CFloat
+foreign import ccall unsafe "math.h remainderf"
+    c_remainderf :: CFloat -> CFloat -> CFloat
 
 default (Double)
diff --git a/numeric-extras.cabal b/numeric-extras.cabal
--- a/numeric-extras.cabal
+++ b/numeric-extras.cabal
@@ -1,6 +1,7 @@
 name:              numeric-extras
-version:           0.0.3
+version:           0.1
 synopsis:          Useful tools from the C standard library
+description:       Useful tools from the C standard library
 homepage:          http://github.com/ekmett/numeric-extras
 bug-reports:       http://github.com/ekmett/numeric-extras/issues
 license:           BSD3
@@ -10,6 +11,8 @@
 category:          Math
 build-type:        Simple
 cabal-version:     >=1.6
+tested-with:       GHC ==7.0.4, GHC ==7.2.2, GHC ==7.4.2,
+                   GHC ==7.6.3, GHC ==7.8.4, GHC ==7.10.2
 
 extra-source-files: .travis.yml CHANGELOG.markdown