diff --git a/src/ff1.rs b/src/ff1.rs
index bf0500d..271bc06 100644
--- a/src/ff1.rs
+++ b/src/ff1.rs
@@ -64,7 +64,7 @@ impl Radix {
             let log_radix = 31 - radix.leading_zeros();
             Radix::PowerTwo {
                 radix,
-                min_len: cmp::max((MIN_RADIX_2_NS_LEN + log_radix - 1) / log_radix, MIN_NS_LEN),
+                min_len: cmp::max(MIN_RADIX_2_NS_LEN.div_ceil(log_radix), MIN_NS_LEN),
                 log_radix: u8::try_from(log_radix).unwrap(),
             }
         } else {
@@ -101,7 +101,7 @@ impl Radix {
         use libm::{ceil, log2};
         match *self {
             Radix::Any { radix, .. } => ceil(v as f64 * log2(f64::from(radix)) / 8f64) as usize,
-            Radix::PowerTwo { log_radix, .. } => ((v * log_radix as usize) + 7) / 8,
+            Radix::PowerTwo { log_radix, .. } => (v * log_radix as usize).div_ceil(8),
         }
     }
 
@@ -204,7 +204,7 @@ fn generate_s<'a, CIPH: BlockEncrypt>(
 ) -> impl Iterator<Item = u8> + 'a {
     r.clone()
         .into_iter()
-        .chain((1..((d + 15) / 16) as u128).flat_map(move |j| {
+        .chain((1..d.div_ceil(16) as u128).flat_map(move |j| {
             let mut block = r.clone();
             for (b, j) in block.iter_mut().zip(j.to_be_bytes().iter()) {
                 *b ^= j;
@@ -260,7 +260,7 @@ impl<CIPH: BlockCipher + BlockEncrypt + Clone> FF1<CIPH> {
         let b = self.radix.calculate_b(v);
 
         // 4. Let d = 4 * ceil(b / 4) + 4.
-        let d = 4 * ((b + 3) / 4) + 4;
+        let d = 4 * b.div_ceil(4) + 4;
 
         // 5. Let P = [1, 2, 1] || [radix] || [10] || [u mod 256] || [n] || [t].
         let mut p = [1, 2, 1, 0, 0, 0, 10, u as u8, 0, 0, 0, 0, 0, 0, 0, 0];
@@ -330,7 +330,7 @@ impl<CIPH: BlockCipher + BlockEncrypt + Clone> FF1<CIPH> {
         let b = self.radix.calculate_b(v);
 
         // 4. Let d = 4 * ceil(b / 4) + 4.
-        let d = 4 * ((b + 3) / 4) + 4;
+        let d = 4 * b.div_ceil(4) + 4;
 
         // 5. Let P = [1, 2, 1] || [radix] || [10] || [u mod 256] || [n] || [t].
         let mut p = [1, 2, 1, 0, 0, 0, 10, u as u8, 0, 0, 0, 0, 0, 0, 0, 0];
diff --git a/src/ff1/alloc.rs b/src/ff1/alloc.rs
index f932fc1..ec84c64 100644
--- a/src/ff1/alloc.rs
+++ b/src/ff1/alloc.rs
@@ -1,7 +1,5 @@
 //! FF1 NumeralString implementations that require a global allocator.
 
-use core::iter;
-
 use alloc::{vec, vec::Vec};
 
 use num_bigint::{BigInt, BigUint, Sign};
@@ -55,7 +53,7 @@ impl Numeral for BigUint {
             let mut bytes = self.to_bytes_le();
             let padding = b - bytes.len();
             bytes.reserve_exact(padding);
-            bytes.extend(iter::repeat(0).take(padding));
+            bytes.extend(std::iter::repeat_n(0, padding));
             bytes.reverse();
             bytes
         }
@@ -97,7 +95,7 @@ impl NumeralString for FlexibleNumeralString {
     type Ops = Self;
 
     fn is_valid(&self, radix: u32) -> bool {
-        self.0.iter().all(|n| (u32::from(*n) < radix))
+        self.0.iter().all(|n| u32::from(*n) < radix)
     }
 
     fn numeral_count(&self) -> usize {
@@ -194,7 +192,7 @@ impl NumeralString for BinaryNumeralString {
         let n = self.numeral_count();
         let u = n / 2;
         let v = n - u;
-        let a_end = (u + 7) / 8;
+        let a_end = u.div_ceil(8);
         let b_start = u / 8;
 
         // FF1 processes the two halves of a numeral string as big-endian integers in the
@@ -242,7 +240,7 @@ impl NumeralString for BinaryNumeralString {
         let a_subslice = self.0[..a_end].iter();
         let b_subslice = self.0[b_start..].iter();
 
-        let (a, b) = if u % 8 == 0 {
+        let (a, b) = if u.is_multiple_of(8) {
             // Simple case: no shifting necessary, just splitting and reversing.
             assert_eq!(a_end, b_start);
 
@@ -297,7 +295,7 @@ impl NumeralString for BinaryNumeralString {
             // Simple case: no shifting necessary, just reversing and joining.
             b.data
                 .into_iter()
-                .chain(a.data.into_iter())
+                .chain(a.data)
                 .map(|b| b.reverse_bits())
                 .rev()
                 .collect()
@@ -384,7 +382,7 @@ impl Operations for BinaryOps {
 
 impl BinaryOps {
     fn new(data: Vec<u8>, num_bits: usize) -> Self {
-        assert_eq!(data.len(), (num_bits + 7) / 8);
+        assert_eq!(data.len(), num_bits.div_ceil(8));
         BinaryOps { data, num_bits }
     }
 
diff --git a/src/ff1/proptests.rs b/src/ff1/proptests.rs
index f44da13..a6f820f 100644
--- a/src/ff1/proptests.rs
+++ b/src/ff1/proptests.rs
@@ -56,7 +56,7 @@ proptest! {
         key in prop::array::uniform32(prop::num::u8::ANY),
         (radix, _, _) in valid_radix(),
     ) {
-        assert!(matches!(FF1::<Aes256>::new(&key, radix), Ok(_)));
+        assert!(FF1::<Aes256>::new(&key, radix).is_ok());
     }
 
     #[test]