diff --git a/tasks/makoveeva_matmul_double_seq/common/include/common.hpp b/tasks/makoveeva_matmul_double_seq/common/include/common.hpp
new file mode 100644
index 000000000..b02a6c4ae
--- /dev/null
+++ b/tasks/makoveeva_matmul_double_seq/common/include/common.hpp
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <cstddef>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include "task/include/task.hpp"
+
+namespace makoveeva_matmul_double_seq {
+
+using InType = std::tuple<size_t, std::vector<double>, std::vector<double>>;
+using OutType = std::vector<double>;
+using TestType = std::tuple<size_t, std::string>;
+using BaseTask = ppc::task::Task<InType, OutType>;
+
+}  // namespace makoveeva_matmul_double_seq
diff --git a/tasks/makoveeva_matmul_double_seq/info.json b/tasks/makoveeva_matmul_double_seq/info.json
new file mode 100644
index 000000000..fef624f46
--- /dev/null
+++ b/tasks/makoveeva_matmul_double_seq/info.json
@@ -0,0 +1,9 @@
+{
+  "student": {
+    "first_name": "Софья",
+    "group_number": "3823Б1ПР1",
+    "last_name": "Маковеева",
+    "middle_name": "Игоревна",
+    "task_number": "1"
+  }
+}
diff --git a/tasks/makoveeva_matmul_double_seq/seq/include/ops_seq.hpp b/tasks/makoveeva_matmul_double_seq/seq/include/ops_seq.hpp
new file mode 100644
index 000000000..91d7d8c6d
--- /dev/null
+++ b/tasks/makoveeva_matmul_double_seq/seq/include/ops_seq.hpp
@@ -0,0 +1,35 @@
+#pragma once
+
+#include <cstddef>
+#include <vector>
+
+#include "makoveeva_matmul_double_seq/common/include/common.hpp"
+#include "task/include/task.hpp"
+
+namespace makoveeva_matmul_double_seq {
+
+class MatmulDoubleSeqTask : public BaseTask {
+ public:
+  static constexpr ppc::task::TypeOfTask GetStaticTypeOfTask() {
+    return ppc::task::TypeOfTask::kSEQ;
+  }
+
+  explicit MatmulDoubleSeqTask(const InType &in);
+
+  bool ValidationImpl() override;
+  bool PreProcessingImpl() override;
+  bool RunImpl() override;
+  bool PostProcessingImpl() override;
+
+  [[nodiscard]] const std::vector<double> &GetResult() const {
+    return C_;
+  }
+
+ private:
+  size_t n_;
+  std::vector<double> A_;
+  std::vector<double> B_;
+  std::vector<double> C_;
+};
+
+}  // namespace makoveeva_matmul_double_seq
diff --git a/tasks/makoveeva_matmul_double_seq/seq/src/ops_seq.cpp b/tasks/makoveeva_matmul_double_seq/seq/src/ops_seq.cpp
new file mode 100644
index 000000000..738a9dc3b
--- /dev/null
+++ b/tasks/makoveeva_matmul_double_seq/seq/src/ops_seq.cpp
@@ -0,0 +1,87 @@
+#include "makoveeva_matmul_double_seq/seq/include/ops_seq.hpp"
+
+#include <algorithm>
+#include <cmath>
+#include <vector>
+
+#include "makoveeva_matmul_double_seq/common/include/common.hpp"  // для InType
+
+namespace makoveeva_matmul_double_seq {
+namespace {
+
+void ProcessBlock(const std::vector<double> &a, const std::vector<double> &b, std::vector<double> &c, int n,
+                  int i_start, int i_end, int j_start, int j_end, int k_start, int k_end) {
+  for (int i = i_start; i < i_end; ++i) {
+    for (int j = j_start; j < j_end; ++j) {
+      double sum = 0.0;
+      for (int k = k_start; k < k_end; ++k) {
+        sum += a[(i * n) + k] * b[(k * n) + j];
+      }
+      c[(i * n) + j] += sum;
+    }
+  }
+}
+
+int CalculateBlockSize(int n) {
+  return std::max(1, static_cast<int>(std::sqrt(static_cast<double>(n))));
+}
+
+int CalculateNumBlocks(int n, int block_size) {
+  return (n + block_size - 1) / block_size;
+}
+
+}  // namespace
+
+MatmulDoubleSeqTask::MatmulDoubleSeqTask(const InType &in)
+    : n_(std::get<0>(in)), A_(std::get<1>(in)), B_(std::get<2>(in)), C_(n_ * n_, 0.0) {
+  SetTypeOfTask(GetStaticTypeOfTask());
+  GetOutput() = C_;
+}
+
+bool MatmulDoubleSeqTask::ValidationImpl() {
+  const bool valid_n = n_ > 0;
+  const bool valid_a = A_.size() == n_ * n_;
+  const bool valid_b = B_.size() == n_ * n_;
+  return valid_n && valid_a && valid_b;
+}
+
+bool MatmulDoubleSeqTask::PreProcessingImpl() {
+  return true;
+}
+
+bool MatmulDoubleSeqTask::RunImpl() {
+  if (n_ <= 0) {
+    return false;
+  }
+
+  // Очищаем C_ перед вычислениями
+  C_.assign(C_.size(), 0.0);
+
+  const int n_int = static_cast<int>(n_);
+  const int block_size = CalculateBlockSize(n_int);
+  const int num_blocks = CalculateNumBlocks(n_int, block_size);
+
+  for (int ib = 0; ib < num_blocks; ++ib) {
+    for (int jb = 0; jb < num_blocks; ++jb) {
+      for (int kb = 0; kb < num_blocks; ++kb) {
+        const int i_start = ib * block_size;
+        const int i_end = std::min(i_start + block_size, n_int);
+        const int j_start = jb * block_size;
+        const int j_end = std::min(j_start + block_size, n_int);
+        const int k_start = kb * block_size;
+        const int k_end = std::min(k_start + block_size, n_int);
+
+        ProcessBlock(A_, B_, C_, n_int, i_start, i_end, j_start, j_end, k_start, k_end);
+      }
+    }
+  }
+
+  GetOutput() = C_;
+  return true;
+}
+
+bool MatmulDoubleSeqTask::PostProcessingImpl() {
+  return true;
+}
+
+}  // namespace makoveeva_matmul_double_seq
diff --git a/tasks/makoveeva_matmul_double_seq/settings.json b/tasks/makoveeva_matmul_double_seq/settings.json
new file mode 100644
index 000000000..0be0208fc
--- /dev/null
+++ b/tasks/makoveeva_matmul_double_seq/settings.json
@@ -0,0 +1,10 @@
+{
+  "tasks": {
+    "all": "enabled",
+    "omp": "enabled",
+    "seq": "enabled",
+    "stl": "enabled",
+    "tbb": "enabled"
+  },
+  "tasks_type": "threads"
+}
diff --git a/tasks/makoveeva_matmul_double_seq/tests/functional/main.cpp b/tasks/makoveeva_matmul_double_seq/tests/functional/main.cpp
new file mode 100644
index 000000000..36f893a61
--- /dev/null
+++ b/tasks/makoveeva_matmul_double_seq/tests/functional/main.cpp
@@ -0,0 +1,99 @@
+#include <gtest/gtest.h>
+
+#include <cmath>
+#include <cstddef>
+#include <tuple>
+#include <vector>
+
+#include "makoveeva_matmul_double_seq/seq/include/ops_seq.hpp"
+
+namespace makoveeva_matmul_double_seq {
+namespace {
+
+void ReferenceMultiply(const std::vector<double> &a, const std::vector<double> &b, std::vector<double> &c, size_t n) {
+  for (size_t i = 0; i < n; ++i) {
+    for (size_t k = 0; k < n; ++k) {
+      const double tmp = a[(i * n) + k];
+      for (size_t j = 0; j < n; ++j) {
+        c[(i * n) + j] += tmp * b[(k * n) + j];
+      }
+    }
+  }
+}
+
+// Разбиваем функцию на еще более мелкие части
+void ValidateTask(MatmulDoubleSeqTask &task) {
+  ASSERT_TRUE(task.ValidationImpl());
+}
+
+void PreProcessTask(MatmulDoubleSeqTask &task) {
+  ASSERT_TRUE(task.PreProcessingImpl());
+}
+
+void RunTask(MatmulDoubleSeqTask &task) {
+  ASSERT_TRUE(task.RunImpl());
+}
+
+void PostProcessTask(MatmulDoubleSeqTask &task) {
+  ASSERT_TRUE(task.PostProcessingImpl());
+}
+
+void CheckTaskExecution(MatmulDoubleSeqTask &task) {
+  ValidateTask(task);
+  PreProcessTask(task);
+  RunTask(task);
+  PostProcessTask(task);
+}
+
+void CheckResults(const std::vector<double> &result, const std::vector<double> &expected) {
+  ASSERT_EQ(result.size(), expected.size());
+  const double epsilon = 1e-10;
+  for (size_t i = 0; i < result.size(); ++i) {
+    ASSERT_NEAR(result[i], expected[i], epsilon);
+  }
+}
+
+}  // namespace
+
+TEST(MatmulDoubleFunctionalTest, multiply2x2) {
+  const size_t n = 2;
+  const std::vector<double> a = {1.0, 2.0, 3.0, 4.0};
+  const std::vector<double> b = {5.0, 6.0, 7.0, 8.0};
+  const std::vector<double> expected = {19.0, 22.0, 43.0, 50.0};
+
+  auto input = std::make_tuple(n, a, b);
+  MatmulDoubleSeqTask task(input);
+
+  CheckTaskExecution(task);
+  CheckResults(task.GetResult(), expected);
+}
+
+TEST(MatmulDoubleFunctionalTest, multiply3x3) {
+  const size_t n = 3;
+  const std::vector<double> a = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0};
+  const std::vector<double> b = {9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, 1.0};
+  const std::vector<double> expected = {30.0, 24.0, 18.0, 84.0, 69.0, 54.0, 138.0, 114.0, 90.0};
+
+  auto input = std::make_tuple(n, a, b);
+  MatmulDoubleSeqTask task(input);
+
+  CheckTaskExecution(task);
+  CheckResults(task.GetResult(), expected);
+}
+
+TEST(MatmulDoubleFunctionalTest, multiply4x4) {
+  const size_t n = 4;
+  const std::vector<double> a = {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0};
+  const std::vector<double> b = {16.0, 15.0, 14.0, 13.0, 12.0, 11.0, 10.0, 9.0, 8.0, 7.0, 6.0, 5.0, 4.0, 3.0, 2.0, 1.0};
+
+  std::vector<double> expected(n * n, 0.0);
+  ReferenceMultiply(a, b, expected, n);
+
+  auto input = std::make_tuple(n, a, b);
+  MatmulDoubleSeqTask task(input);
+
+  CheckTaskExecution(task);
+  CheckResults(task.GetResult(), expected);
+}
+
+}  // namespace makoveeva_matmul_double_seq
diff --git a/tasks/makoveeva_matmul_double_seq/tests/performance/main.cpp b/tasks/makoveeva_matmul_double_seq/tests/performance/main.cpp
new file mode 100644
index 000000000..b37363ed3
--- /dev/null
+++ b/tasks/makoveeva_matmul_double_seq/tests/performance/main.cpp
@@ -0,0 +1,93 @@
+#include <gtest/gtest.h>
+
+#include <cmath>    // для std::abs
+#include <cstddef>  // для size_t
+#include <tuple>
+#include <vector>
+
+#include "makoveeva_matmul_double_seq/common/include/common.hpp"
+#include "makoveeva_matmul_double_seq/seq/include/ops_seq.hpp"
+#include "util/include/perf_test_util.hpp"
+
+namespace makoveeva_matmul_double_seq {
+namespace {
+
+void ReferenceMultiply(const std::vector<double> &a, const std::vector<double> &b, std::vector<double> &c, size_t n) {
+  // Очищаем c перед вычислениями - используем assign вместо цикла
+  c.assign(c.size(), 0.0);
+
+  for (size_t i = 0; i < n; ++i) {
+    for (size_t k = 0; k < n; ++k) {
+      const double tmp = a[(i * n) + k];
+      for (size_t j = 0; j < n; ++j) {
+        c[(i * n) + j] += tmp * b[(k * n) + j];
+      }
+    }
+  }
+}
+
+}  // namespace
+
+class MatmulDoublePerformanceTest : public ppc::util::BaseRunPerfTests<InType, OutType> {
+  InType input_data_;
+  std::vector<double> expected_output_;
+
+ protected:
+  void SetUp() override {
+    const size_t n = 400;
+    const size_t size = n * n;
+
+    std::vector<double> a(size);
+    std::vector<double> b(size);
+
+    for (size_t i = 0; i < size; ++i) {
+      a[i] = static_cast<double>(i + 1);
+      b[i] = static_cast<double>(size - i);
+    }
+
+    input_data_ = std::make_tuple(n, a, b);
+
+    expected_output_.resize(size);
+    ReferenceMultiply(a, b, expected_output_, n);
+  }
+
+  bool CheckTestOutputData(OutType &output_data) final {
+    const auto &expected = expected_output_;
+    const auto &actual = output_data;
+
+    if (expected.size() != actual.size()) {
+      return false;
+    }
+
+    const double epsilon = 1e-7;
+    for (size_t i = 0; i < expected.size(); ++i) {
+      if (std::abs(expected[i] - actual[i]) > epsilon) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  InType GetTestInputData() final {
+    return input_data_;
+  }
+};
+
+TEST_P(MatmulDoublePerformanceTest, RunPerfModes) {
+  ExecuteTest(GetParam());
+}
+
+namespace {
+
+const auto kAllPerfTasks =
+    ppc::util::MakeAllPerfTasks<InType, MatmulDoubleSeqTask>(PPC_SETTINGS_makoveeva_matmul_double_seq);
+
+const auto kGtestValues = ppc::util::TupleToGTestValues(kAllPerfTasks);
+
+const auto kPerfTestName = MatmulDoublePerformanceTest::CustomPerfTestName;
+
+INSTANTIATE_TEST_SUITE_P(RunModeTests, MatmulDoublePerformanceTest, kGtestValues, kPerfTestName);
+
+}  // namespace
+
+}  // namespace makoveeva_matmul_double_seq