diff --git a/examples/decimal/decimal.php b/examples/decimal/decimal.php
new file mode 100644
index 00000000..51dc65f4
--- /dev/null
+++ b/examples/decimal/decimal.php
@@ -0,0 +1,10 @@
+<?php
+
+use decimal_types;
+
+function main()
+{
+    $a = 0.1 + 0.2;
+    $b = 1000;
+    echo $a, $b;
+}
\ No newline at end of file
diff --git a/src/Php/CompilerBase.php b/src/Php/CompilerBase.php
index 0b6e6222..4c65356d 100644
--- a/src/Php/CompilerBase.php
+++ b/src/Php/CompilerBase.php
@@ -1781,7 +1781,16 @@ class CompilerBase extends \PhpAot\Core\Translator
             if ($expr instanceof Expr\Assign) {
                 $this->fatalError($expr, 'Cannot echo assign expression');
             } else {
-                $lines[] = 'php::echo(' . $this->parseExpr($expr) . ');';
+                $type = $this->detectTypeOfExpr($expr);
+                $parsed = $this->parseExpr($expr);
+                if ($type === self::TYPE_BIGINT) {
+                    $parsed = 'php::BigInt::toString(' . $parsed . ')';
+                } elseif ($type === self::TYPE_BIGFLOAT) {
+                    $parsed = 'php::BigFloat::toString(' . $parsed . ')';
+                } elseif ($type === self::TYPE_DECIMAL) {
+                    $parsed = 'php::Decimal::toString(' . $parsed . ')';
+                }
+                $lines[] = 'php::echo(' . $parsed . ');';
             }
         }
 
@@ -2460,6 +2469,25 @@ class CompilerBase extends \PhpAot\Core\Translator
             case 'Expr_FuncCall':
                 if ($this->isNameExpr($expr->name)) {
                     $name = $this->parseIdentifier($expr->name);
+                    // Math function optimization: propagate Big* return types
+                    if (in_array($name, ['abs', 'pow', 'sqrt', 'floor', 'ceil', 'round'], true) && !empty($expr->args)) {
+                        $argType = $this->detectTypeOfExpr($expr->args[0]->value);
+                        if (
+                            $argType === self::TYPE_BIGINT
+                            && in_array($name, ['abs', 'pow', 'sqrt'], true)
+                        ) {
+                            return self::TYPE_BIGINT;
+                        }
+                        if (
+                            $argType === self::TYPE_DECIMAL
+                            && in_array($name, ['abs', 'pow', 'sqrt', 'floor', 'ceil', 'round'], true)
+                        ) {
+                            return self::TYPE_DECIMAL;
+                        }
+                        if ($argType === self::TYPE_BIGFLOAT && $name === 'abs') {
+                            return self::TYPE_BIGFLOAT;
+                        }
+                    }
                     if (in_array($name, self::STREAM_FUNCTIONS) || $name === 'stream_cast') {
                         return self::TYPE_STREAM;
                     }
@@ -2976,15 +3004,29 @@ class CompilerBase extends \PhpAot\Core\Translator
 
     protected function parseBinaryOpConcat(Expr\BinaryOp\Concat $expr): string
     {
-        $left = $this->parseIdentifier($expr->left);
-        $right = $this->parseIdentifier($expr->right);
+        $left = $this->parseExpr($expr->left);
+        $right = $this->parseExpr($expr->right);
 
         $leftType = $this->detectTypeOfExpr($expr->left);
         $rightType = $this->detectTypeOfExpr($expr->right);
         if ($leftType === self::TYPE_VOID or $rightType === self::TYPE_VOID) {
             $this->fatalError($expr, 'Cannot concat void');
         }
-        return Symbol::concat() . '(' . $this->convertStringExpr($left) . ', ' . $this->convertStringExpr($right) . ')';
+        return Symbol::concat() . '(' . $this->convertExprToStringByType($left, $leftType) . ', ' . $this->convertExprToStringByType($right, $rightType) . ')';
+    }
+
+    protected function convertExprToStringByType(string $expr, $type): string
+    {
+        if ($type === self::TYPE_BIGINT) {
+            return 'php::BigInt::toString(' . $expr . ')';
+        }
+        if ($type === self::TYPE_BIGFLOAT) {
+            return 'php::BigFloat::toString(' . $expr . ')';
+        }
+        if ($type === self::TYPE_DECIMAL) {
+            return 'php::Decimal::toString(' . $expr . ')';
+        }
+        return $this->convertStringExpr($expr);
     }
 
     protected function parseFor(Node\Stmt\For_ $v): string
@@ -4348,7 +4390,18 @@ class CompilerBase extends \PhpAot\Core\Translator
 
     protected function parseCastString(Expr\Cast\String_ $node): string
     {
-        return $this->convertStringExpr($this->parseExpr($node->expr));
+        $type = $this->detectTypeOfExpr($node->expr);
+        $expr = $this->parseExpr($node->expr);
+        if ($type === self::TYPE_BIGINT) {
+            return 'php::BigInt::toString(' . $expr . ')';
+        }
+        if ($type === self::TYPE_BIGFLOAT) {
+            return 'php::BigFloat::toString(' . $expr . ')';
+        }
+        if ($type === self::TYPE_DECIMAL) {
+            return 'php::Decimal::toString(' . $expr . ')';
+        }
+        return $this->convertStringExpr($expr);
     }
 
     protected function parseCastBool(Expr\Cast\Bool_ $node): string
diff --git a/src/Php/FuncCallOptimizer.php b/src/Php/FuncCallOptimizer.php
index edc124c6..278c22c0 100644
--- a/src/Php/FuncCallOptimizer.php
+++ b/src/Php/FuncCallOptimizer.php
@@ -69,7 +69,19 @@ trait FuncCallOptimizer
                 case 'boolval':
                     return $this->convertBoolExpr($this->parseExpr($expr->args[0]->value));
                 case 'strval':
-                    return $this->convertStringExpr($this->parseExpr($expr->args[0]->value));
+                    $arg = $expr->args[0]->value;
+                    $type = $this->detectTypeOfExpr($arg);
+                    $parsed = $this->parseExpr($arg);
+                    if ($type === self::TYPE_BIGINT) {
+                        return 'php::BigInt::toString(' . $parsed . ')';
+                    }
+                    if ($type === self::TYPE_BIGFLOAT) {
+                        return 'php::BigFloat::toString(' . $parsed . ')';
+                    }
+                    if ($type === self::TYPE_DECIMAL) {
+                        return 'php::Decimal::toString(' . $parsed . ')';
+                    }
+                    return $this->convertStringExpr($parsed);
                 default:
                     break;
             }
@@ -91,11 +103,59 @@ trait FuncCallOptimizer
             }
         }
         if ($name === 'abs') {
+            $type = $this->detectTypeOfExpr($expr->args[0]->value);
+            if ($type === self::TYPE_BIGINT) {
+                return 'php::BigInt::abs(' . $this->parseExpr($expr->args[0]->value) . ')';
+            }
+            if ($type === self::TYPE_BIGFLOAT) {
+                return 'php::BigFloat::abs(' . $this->parseExpr($expr->args[0]->value) . ')';
+            }
+            if ($type === self::TYPE_DECIMAL) {
+                return 'php::Decimal::abs(' . $this->parseExpr($expr->args[0]->value) . ')';
+            }
             return 'php::math::abs(' . $getArg(0) . ')';
         }
         if ($name === 'pow') {
+            $type = $this->detectTypeOfExpr($expr->args[0]->value);
+            if ($type === self::TYPE_BIGINT) {
+                return 'php::BigInt::pow(' . $this->parseExpr($expr->args[0]->value) . ', ' . $this->parseExpr($expr->args[1]->value) . ')';
+            }
+            if ($type === self::TYPE_DECIMAL) {
+                return 'php::Decimal::pow(' . $this->parseExpr($expr->args[0]->value) . ', ' . $this->parseExpr($expr->args[1]->value) . ')';
+            }
             return 'php::math::pow(' . $getArg(0) . ', ' . $getArg(1) . ')';
         }
+        if ($name === 'sqrt') {
+            $type = $this->detectTypeOfExpr($expr->args[0]->value);
+            if ($type === self::TYPE_BIGINT) {
+                return 'php::BigInt::sqrt(' . $this->parseExpr($expr->args[0]->value) . ')';
+            }
+            if ($type === self::TYPE_DECIMAL) {
+                return 'php::Decimal::sqrt(' . $this->parseExpr($expr->args[0]->value) . ')';
+            }
+        }
+        if ($name === 'floor') {
+            $type = $this->detectTypeOfExpr($expr->args[0]->value);
+            if ($type === self::TYPE_DECIMAL) {
+                return 'php::Decimal::floor(' . $this->parseExpr($expr->args[0]->value) . ')';
+            }
+        }
+        if ($name === 'ceil') {
+            $type = $this->detectTypeOfExpr($expr->args[0]->value);
+            if ($type === self::TYPE_DECIMAL) {
+                return 'php::Decimal::ceil(' . $this->parseExpr($expr->args[0]->value) . ')';
+            }
+        }
+        if ($name === 'round') {
+            $type = $this->detectTypeOfExpr($expr->args[0]->value);
+            if ($type === self::TYPE_DECIMAL) {
+                $arg0 = $this->parseExpr($expr->args[0]->value);
+                if (count($expr->args) >= 2) {
+                    return 'php::Decimal::round(' . $arg0 . ', ' . $this->parseExpr($expr->args[1]->value) . ')';
+                }
+                return 'php::Decimal::round(' . $arg0 . ')';
+            }
+        }
         if ($name === 'strlen') {
             return 'php::fn::strlen(' . $getArg(0) . ')';
         }
diff --git a/tests/aot/bigint/math_func_opt.phpt b/tests/aot/bigint/math_func_opt.phpt
new file mode 100644
index 00000000..70526db9
--- /dev/null
+++ b/tests/aot/bigint/math_func_opt.phpt
@@ -0,0 +1,33 @@
+--TEST--
+Big* types: math function optimization (abs/pow/sqrt/floor/ceil/round)
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    // BigInt
+    $a = std::bigInt("100");
+    $a1 = abs($a);
+    $a2 = pow($a, 2);
+    $a3 = sqrt($a);
+
+    // Decimal
+    $b = std::decimal("3.14");
+    $b1 = abs($b);
+    $b2 = pow($b, 3);
+    $b3 = sqrt($b);
+    $b4 = floor($b);
+    $b5 = ceil($b);
+    $b6 = round($b);
+    $b7 = round(std::decimal("3.14159"), 2);
+
+    // BigFloat
+    $c = std::bigFloat("-2.5");
+    $c1 = abs($c);
+
+    echo "OK\n";
+}
+?>
+--EXPECT--
+OK
diff --git a/tests/aot/bigint/toString_cast.phpt b/tests/aot/bigint/toString_cast.phpt
new file mode 100644
index 00000000..7de4513f
--- /dev/null
+++ b/tests/aot/bigint/toString_cast.phpt
@@ -0,0 +1,37 @@
+--TEST--
+Big* types: (string) cast, strval() and echo → toString()
+--FILE--
+<?php
+declare(strict_types=1);
+use native_types;
+
+function main(): void {
+    // BigInt
+    $a = std::bigInt("12345678901234567890");
+    var_dump((string) $a);
+    var_dump(strval($a));
+    echo $a; echo "\n";
+
+    // BigFloat
+    $b = std::bigFloat("3.141592653589793");
+    var_dump((string) $b);
+    var_dump(strval($b));
+    echo $b; echo "\n";
+
+    // Decimal
+    $c = std::decimal("0.123456789");
+    var_dump((string) $c);
+    var_dump(strval($c));
+    echo $c; echo "\n";
+}
+?>
+--EXPECT--
+string(20) "12345678901234567890"
+string(20) "12345678901234567890"
+12345678901234567890
+string(18) "3.1415926535897931"
+string(18) "3.1415926535897931"
+3.1415926535897931
+string(11) "0.123456789"
+string(11) "0.123456789"
+0.123456789
diff --git a/tests/aot/decimal/floor-02.phpt b/tests/aot/decimal/floor-02.phpt
new file mode 100644
index 00000000..5c4abf42
--- /dev/null
+++ b/tests/aot/decimal/floor-02.phpt
@@ -0,0 +1,17 @@
+--TEST--
+decimal: literal
+--FILE--
+<?php
+use decimal_types;
+
+function main()
+{
+    require __DIR__ . '/../../../src/Assert.php';
+    $amount = 19.99;
+    $rate = 0.09;
+    $tax = $amount * $rate;  // 1.7991 —— Decimal 精确计算
+    echo floor($tax * 100) / 100.0;  // floor(179.91) / 100.0 = 1.79
+}
+?>
+--EXPECT--
+1.79
\ No newline at end of file
diff --git a/tests/aot/decimal/round-02.phpt b/tests/aot/decimal/round-02.phpt
new file mode 100644
index 00000000..fb1610c9
--- /dev/null
+++ b/tests/aot/decimal/round-02.phpt
@@ -0,0 +1,25 @@
+--TEST--
+Decimal: round
+--FILE--
+<?php
+use decimal_types;
+
+function main(): void {
+    $item1 = 19.99;  // 商品A
+    $item2 = 29.99;  // 商品B
+    $item3 = 39.99;  // 商品C
+    $tax_rate = 0.08;
+
+    $subtotal = $item1 + $item2 + $item3;
+    $tax = $subtotal * $tax_rate;
+    $total = $subtotal + $tax;
+
+    echo "小计: " . round($subtotal, 2) . "\n";        // 89.97
+    echo "税额: " . round($tax, 4) . "\n";             // 7.1976
+    echo "总计: " . round($total, 2) . "\n";           // 97.17
+}
+?>
+--EXPECT--
+小计: 89.97
+税额: 7.1976
+总计: 97.17