diff --git a/Calcium/CalciumApp.swift b/Calcium/CalciumApp.swift
index 3ead7c6..e69d4ea 100644
--- a/Calcium/CalciumApp.swift
+++ b/Calcium/CalciumApp.swift
@@ -7,10 +7,16 @@
 //
 
 import ComposableArchitecture
+import Resolver
 import SwiftUI
 
 @main
 struct CalciumApp: App {
+    init() {
+        Resolver.register { NativeCalculator() }
+            .implements(Calculator.self)
+    }
+
     var body: some Scene {
         WindowGroup {
             MainScreen(
diff --git a/Calcium/Enums.swift b/Calcium/Enums.swift
index 66bb4b2..8f0c6b2 100644
--- a/Calcium/Enums.swift
+++ b/Calcium/Enums.swift
@@ -9,6 +9,21 @@
 import BigNumber
 import CalciumCommon
 
+protocol Calculator {
+    func calculateValue(lhs: String, rhs: String, operation: CalciumCommon.Operation) -> String
+}
+
+struct NativeCalculator: Calculator {
+    func calculateValue(lhs: String, rhs: String, operation: CalciumCommon.Operation) -> String {
+        .init(
+            operation.calculateValue(
+                lhs: .init(lhs) ?? .init(),
+                rhs: .init(rhs) ?? .init()
+            )
+        )
+    }
+}
+
 extension CalciumCommon.Digit: CalciumCommon.CalculatorButtonRepresentable {
     public var displayingValue: String {
         String(value)
diff --git a/Calcium/MainReducer.swift b/Calcium/MainReducer.swift
index a4f5428..b4a76b8 100644
--- a/Calcium/MainReducer.swift
+++ b/Calcium/MainReducer.swift
@@ -9,6 +9,7 @@
 import BigNumber
 import CalciumCommon
 import ComposableArchitecture
+import Resolver
 
 enum MainReducerError: Error {
     case invalidValues
@@ -16,6 +17,8 @@ enum MainReducerError: Error {
 
 @Reducer
 struct MainReducer {
+    @Injected private var calculator: Calculator
+
     @ObservableState
     struct State: Equatable {
         var enabled1 = true
@@ -139,10 +142,8 @@ struct MainReducer {
                             throw MainReducerError.invalidValues
                         }
                         let value = await Task {
-                            operation.calculateValue(
-                                lhs: lhs,
-                                rhs: rhs
-                            )
+                            let result = calculator.calculateValue(lhs: lhs.asString(radix: 10), rhs: rhs.asString(radix: 10), operation: operation)
+                            return BInt(result) ?? .init()
                         }.value
                         await send(.calculated(value), animation: .calciumDefault)
                     }
diff --git a/project.yml b/project.yml
index 534ffd8..0728725 100644
--- a/project.yml
+++ b/project.yml
@@ -11,6 +11,9 @@ packages:
   BigNumber:
     url: https://github.com/mkrd/Swift-BigInt
     version: 2.3.0
+  Resolver:
+    url: https://github.com/hmlongco/Resolver
+    version: 1.5.1
 targets:
   CalciumApp:
     type: application
@@ -20,6 +23,7 @@ targets:
       - framework: CalciumCommon/build/XCFrameworks/release/CalciumCommon.xcframework
       - package: ComposableArchitecture
       - package: BigNumber
+      - package: Resolver
     info:
       path: Calcium/Info.plist
     postCompileScripts: