diff --git a/build/instructions_template.rs b/build/instructions_template.rs
index 8ec818e6..3ac76eff 100644
--- a/build/instructions_template.rs
+++ b/build/instructions_template.rs
@@ -743,6 +743,10 @@ enum InstructionTemplate {
     Ceiling(ArithmeticTerm, usize),
     #[strum_discriminants(strum(props(Arity = "1", Name = "floor")))]
     Floor(ArithmeticTerm, usize),
+    #[strum_discriminants(strum(props(Arity = "1", Name = "float_fractional_part")))]
+    FloatFractionalPart(ArithmeticTerm, usize),
+    #[strum_discriminants(strum(props(Arity = "1", Name = "float_integer_part")))]
+    FloatIntegerPart(ArithmeticTerm, usize),
     #[strum_discriminants(strum(props(Arity = "1", Name = "neg")))]
     Neg(ArithmeticTerm, usize),
     #[strum_discriminants(strum(props(Arity = "1", Name = "plus")))]
@@ -1463,6 +1467,12 @@ fn generate_instruction_preface() -> TokenStream {
                     &Instruction::Floor(ref at, t) => {
                         arith_instr_unary_functor(h, atom!("floor"), arena, at, t)
                     }
+                    &Instruction::FloatFractionalPart(ref at, t) => {
+                        arith_instr_unary_functor(h, atom!("float_fractional_part"), arena, at, t)
+                    }
+                    &Instruction::FloatIntegerPart(ref at, t) => {
+                        arith_instr_unary_functor(h, atom!("float_integer_part"), arena, at, t)
+                    }
                     &Instruction::Neg(ref at, t) => arith_instr_unary_functor(
                         h,
                         atom!("-"),
diff --git a/src/arithmetic.rs b/src/arithmetic.rs
index bc58da50..a75f2efe 100644
--- a/src/arithmetic.rs
+++ b/src/arithmetic.rs
@@ -212,6 +212,8 @@ impl<'a> ArithmeticEvaluator<'a> {
             atom!("round") => Ok(Instruction::Round(a1, t)),
             atom!("ceiling") => Ok(Instruction::Ceiling(a1, t)),
             atom!("floor") => Ok(Instruction::Floor(a1, t)),
+            atom!("float_integer_part") => Ok(Instruction::FloatIntegerPart(a1, t)),
+            atom!("float_fractional_part") => Ok(Instruction::FloatFractionalPart(a1, t)),
             atom!("sign") => Ok(Instruction::Sign(a1, t)),
             atom!("\\") => Ok(Instruction::BitwiseComplement(a1, t)),
             _ => Err(ArithmeticError::NonEvaluableFunctor(Literal::Atom(name), 1)),
diff --git a/src/machine/arithmetic_ops.rs b/src/machine/arithmetic_ops.rs
index 6af111b2..6be49e8d 100644
--- a/src/machine/arithmetic_ops.rs
+++ b/src/machine/arithmetic_ops.rs
@@ -1053,6 +1053,16 @@ pub(crate) fn log10(n1: Number) -> Result<f64, MachineStubGen> {
     unary_float_fn_template(n1, |f| f.log(10f64))
 }
 
+#[inline]
+pub(crate) fn float_fractional_part(n1: Number) -> Result<f64, MachineStubGen> {
+    unary_float_fn_template(n1, |f| f.fract())
+}
+
+#[inline]
+pub(crate) fn float_integer_part(n1: Number) -> Result<f64, MachineStubGen> {
+    unary_float_fn_template(n1, |f| f.trunc())
+}
+
 #[inline]
 pub(crate) fn sqrt(n1: Number) -> Result<f64, MachineStubGen> {
     if n1.is_negative() {
@@ -1072,6 +1082,7 @@ pub(crate) fn floor(n1: Number, arena: &mut Arena) -> Number {
     rnd_i(&n1, arena)
 }
 
+
 #[inline]
 pub(crate) fn ceiling(n1: Number, arena: &mut Arena) -> Number {
     let n1 = neg(n1, arena);
@@ -1323,6 +1334,12 @@ impl MachineState {
                             atom!("log10") => self.interms.push(Number::Float(OrderedFloat(
                                 drop_iter_on_err!(self, iter, log10(a1))
                             ))),
+                            atom!("float_fractional_part") => self.interms.push(Number::Float(OrderedFloat(
+                                drop_iter_on_err!(self, iter, float_fractional_part(a1))
+                            ))),
+                            atom!("float_integer_part") => self.interms.push(Number::Float(OrderedFloat(
+                                drop_iter_on_err!(self, iter, float_integer_part(a1))
+                            ))),
                             atom!("sqrt") => self.interms.push(Number::Float(OrderedFloat(
                                 drop_iter_on_err!(self, iter, sqrt(a1))
                             ))),
diff --git a/src/machine/dispatch.rs b/src/machine/dispatch.rs
index 8f7e3e91..fbfa6580 100644
--- a/src/machine/dispatch.rs
+++ b/src/machine/dispatch.rs
@@ -1028,6 +1028,24 @@ impl Machine {
                     self.machine_st.interms[t - 1] = floor(n1, &mut self.machine_st.arena);
                     self.machine_st.p += 1;
                 }
+                &Instruction::FloatFractionalPart(ref a1, t) => {
+                    let n1 = try_or_throw!(self.machine_st, self.machine_st.get_number(a1));
+
+                    self.machine_st.interms[t - 1] = Number::Float(OrderedFloat(
+                        try_or_throw_gen!(&mut self.machine_st, float_fractional_part(n1))
+                    ));
+
+                    self.machine_st.p += 1;
+                }
+                &Instruction::FloatIntegerPart(ref a1, t) => {
+                    let n1 = try_or_throw!(self.machine_st, self.machine_st.get_number(a1));
+
+                    self.machine_st.interms[t - 1] = Number::Float(OrderedFloat(
+                        try_or_throw_gen!(&mut self.machine_st, float_integer_part(n1))
+                    ));
+
+                    self.machine_st.p += 1;
+                }
                 &Instruction::Plus(ref a1, t) => {
                     let n1 = try_or_throw!(self.machine_st, self.machine_st.get_number(a1));