```xml
<?xml version="1.0" encoding="UTF-8"?>
<game>
  <title>Equation Ten</title>
  <slug>equation-ten</slug>
  <short-desc>Craft expressions that equal 10 in this engaging math puzzle! Select numbers and operators from the grid to build winning equations.</short-desc>
  <categories>
    <category>Puzzle</category>
    <category>Math</category>
    <category>Educational</category>
  </categories>
  <keywords>math game, puzzle game, equation game, number puzzle, brain teaser, logic game, educational game, HTML5 game, arithmetic, make 10</keywords>
  <content>
# About Equation Ten

Equation Ten is a captivating math puzzle game where your goal is to strategically combine numbers and operators to form expressions that evaluate to exactly 10. The game presents you with an 8x8 grid filled with randomly generated numbers (1-9) and arithmetic operators (+, -, ×, ÷).

Challenge your numerical and logical skills by selecting items from the grid and arranging them in an 8-slot inventory bar. As you build your expression, the game provides real-time feedback on its current value. Successfully create an equation that equals 10, and you'll score points based on the number of items used. These items are then cleared from play, making subsequent equations potentially more challenging as the grid depletes.

## How to Play

1.  **Survey the Grid**: The game starts with an 8x8 grid populated with numbers (1-9) and operators (+, -, ×, ÷).
2.  **Select Items**: Click on a number or operator tile in the grid to select it. The selected item will be highlighted.
3.  **Build Your Equation**: Click on an empty slot in the 8-slot inventory bar located below the grid. The selected item from the grid will move into this slot.
4.  **Arrange and Rearrange**:
    *   To return an item from the inventory back to its original spot in the grid: first, click the item in the inventory to select it, then click its now-empty original cell in the grid.
    *   You can only place items from the grid into empty inventory slots.
5.  **Evaluate**: The game automatically evaluates the expression in your inventory from left to right as you add items. The message area will display the current expression and its result, or any errors (like "Syntax Error" or "Division by Zero").
6.  **Target Ten**: Your objective is to make the expression in the inventory evaluate to exactly 10.
7.  **Score Points & Clear Items**: If your expression equals 10, you score points equal to the number of items used in that equation. These items are then permanently removed from the inventory and the grid, leaving those grid cells empty.
8.  **Continue Playing**: Keep forming equations with the remaining items on the grid to maximize your score. The grid does not automatically refill with new items.

## Features

- **Dynamic Puzzle Grid**: An 8x8 grid initially filled with numbers (1-9) and operators (+, -, ×, ÷) for diverse puzzle challenges.
- **Interactive Inventory**: An 8-slot bar to construct and visualize your mathematical expressions.
- **Real-time Evaluation**: Get instant feedback on your current expression, including its value or any syntax errors. The game calculates left-to-right.
- **Scoring System**: Earn points for each successful equation that equals 10, with more points awarded for using more items.
- **Responsive Design**: Playable on various screen sizes, adapting for a comfortable experience on both desktop and mobile devices.
- **Clear Item Mechanic**: Successfully used items are removed from the grid, adding a strategic layer as resources become scarcer.

## Controls

- **Mouse Click / Touch Tap**:
    - Click/tap a grid item (if not already in a slot) to select it.
    - Click/tap an empty inventory slot to move the currently selected grid item there.
    - Click/tap an item in the inventory to select it.
    - Click/tap the original (now empty) grid cell of a selected inventory item to return it to the grid.
    - Clicking a selected item (either in grid or inventory) again will deselect it.

## Tips & Strategies

- **Left-to-Right Calculation**: Remember the game calculates strictly from left to right, not following standard PEMDAS/BODMAS. For example, `2 + 3 × 2` will be evaluated as `(2 + 3) × 2 = 10`.
- **Start Simple**: Look for easy two or three-item combinations to make 10, especially when many items are available. This helps clear space and build your score.
- **Plan for Scarcity**: As items are removed, the puzzle becomes more challenging. Think a few steps ahead about how clearing certain numbers or operators will affect future possibilities.
- **Utilize All Operators**: Don't shy away from division or multiplication. They can be key to reaching 10 with specific number sets. Watch out for division by zero!
- **Longer Equations, More Points**: While harder to form, using more items in a successful equation yields a higher score.
  </content>
  <faq>
    <question>How do I save my progress in the game?</question>
    <answer>This game is session-based. Your score will reset if you close or refresh the browser window. There is no persistent save feature.</answer>
    
    <question>Can I play this game on mobile devices?</question>
    <answer>Yes, Equation Ten is designed to be responsive and playable on most modern mobile browsers.</answer>
    
    <question>Is this game free to play?</question>
    <answer>Yes, the game is completely free to play in your browser.</answer>
  </faq>
  <specifications>
    <multiplayer>false</multiplayer>
  </specifications>
</game>
```

An interactive game created with AI assistance