## Add and Subtract with Negative Numbers

Keep the party pumping in this fast n’ furious piñata smash-‘em-up! Move along the number line to intercept the descending piñatas, and then whack them for candy. Come on, catch the fever!

### Instructions

#### Game Goals

In this maths game you’re the host of a crazy piñata party. To keep the party pumping you need to keep the candy jar topped up – and the only way to get more candy is by smashing piñatas!

These colourful, goody-stuffed toys descend slowly from the top of the play area. You must move quickly to intercept them by adding and subtracting positive and negative numbers. Once in position, smash open the piñatas to release their tasty treats!

Think fast because if you run out of candy, the party’s over!

#### How To Play

To start a game, click ‘Play’ and then select a Mode. The tougher the mode, the more points you score. The first time you play, only the easiest Mode is available.

Now click either Carlito or Carlita to select your favourite hero and begin play. (There are no differences between the two heroes other than the way they look.)

Piñatas appear randomly along the top of the play area and start to descend slowly toward the number line. Your task is to intercept and smash the piñatas in order to grab the candy inside.

You move the hero by clicking on the number line and then answering a maths problem:

- Answer the problem
**correctly**and you see the hero move to your chosen position. - Answer the problem
**incorrectly**and you see the hero move to the position as indicated by your incorrect input, shake their head, and then move back to their original position, all of which costs precious time.

Once the hero is beneath a piñata, you get the chance to smash it! A strike meter appears over the hero’s head:

- Stop the meter in the
**blue**zone and you miss the strike, wasting time. But don’t worry, you can try again! - Stop the meter in the
**yellow**zone and you whack the piñata, earning you points and candy. - Stop the meter in the
**red**zone and you smash the piñata’s critical ‘Sweet Spot’, winning you points and even more candy. Sometimes you also make a special Gift Box fly out.

To collect Gift Boxes, move your hero to its position in the usual way; the box will be picked up automatically. Gift Boxes contain presents such as bonus points and special power-ups, so they’re well worth grabbing!

If a piñata gets too close to the number line it will be stolen by El Nibblo, the notorious sweet-toothed piñata thief, and you lose precious candy.

Candy is important as it keeps your hungry guests happy. Your candy count is shown in the top-middle of the screen. If you run out of candy, the party ends – game over! How long can you keep your party going?

#### Game Controls

The game can be controlled entirely with the mouse, or by a combination of mouse and keyboard.

To move the hero, first click on the number line where you want your hero to go. You can only move to positions where there are piñatas or Gift Boxes; the ‘X’ cursor will change from solid to see-through if a move is not allowed.

When you select a position, a maths problem appears in a panel at the bottom of the screen. Use the keypad to input a value for ‘?’. Your input defaults to a positive number, but you can change it to a negative number by clicking the [–] button (and back again by clicking the [+] button). When you’re happy with your value, click on the panel to confirm the input.

When in Window mode, you can also use the keyboard to input values. Use the [+] and [–] keys to toggle between positive and negative numbers, and the Enter key to confirm inputs.

To stop the strike meter, simply click the mouse. Stop the meter in the yellow or red zones to smash the piñata.

#### Gift Boxes & Power-Ups

If you hit a piñata’s ‘Sweet Spot’ (i.e. stop the strike meter in the red zone), sometimes you will see a Gift Box fly out and land on the number line.

To collect a Gift Box you simply move the hero to its position. The box then opens automatically to reveal a present ranging from bonus points to power-ups:

**×1 Bonus**– Points equivalent to the current stage’s piñata score.**×2 Bonus**– Points equivalent to the current stage’s piñata score × 2.**×3 Bonus**– Points equivalent to the current stage’s piñata score × 3.**×5 Bonus**– Points equivalent to the current stage’s piñata score × 5.**Magic Trainers**– Increases the hero’s movement speed for a few moments.**Shockwave**– Pushes all piñatas in view back up toward the top of the screen.**Super Striker**– Temporarily improves the hero’s accuracy, making it easier to hit piñatas.**Cold Snap**– Freezes the piñatas for a few moments, stopping them descending.

The present you receive is chosen randomly. However, the fancier the Gift Box, the more valuable the present inside.

To get fancier Gift Boxes, you need to hit multiple Sweet Spots in a row. Each time you hit a Sweet Spot, the gauge in the top-right corner of the screen fills by one, meaning that your next Gift Box will be even better.

But be warned: as the gauge fills, the strike meter gets faster too! If you miss a piñata or perform a ‘normal’ smash (i.e. stop the strike meter in the yellow zone), the gauge resets.

#### Modes & Stages

This game features three Modes, each offering increasingly difficult maths problems. But it’s not all bad news, as the points you earn increase too!

When you first play, only the first and easiest Mode is unlocked and playable. By achieving a Bronze medal you unlock the second Mode, and by achieving a Bronze Medal in the second Mode you unlock the third Mode.

The maths problems take the form of either **A + ? = B** or **A - ? = B**, where **A** is the hero’s current position on the number line, **B** is the position you want the hero to move to, and **?** is the value you need to input.

**
Mode 1: Adding/Subtracting Positive Numbers **

- When moving to the
__right__all problems are**A + ? = B**(**?**is always a positive number). - When moving to the
__left__all problems are**A - ? = B**(**?**is always a positive number).

**
Mode 2: Adding/Subtracting Positive Numbers & Adding Negative Numbers **

- When moving to the
__right__all problems are**A + ? = B**(**?**is always a positive number). - When moving to the
__left__problems are either:

**A - ? = B**(**?**is a positive number), or…

**A + ? = B**(**?**is a negative number).

**
Mode 3: Adding/Subtracting Positive & Negative Numbers **

- When moving to the
__right__problems are either:

**A + ? = B**(**?**is a positive number), or…

**A - ? = B**(**?**is a negative number). - When moving to the
__left__problems are either:

**A - ? = B**((**?**is a positive number), or…

**A + ? = B**((**?**is a negative number).

Within each Mode there are 24 individual Stages to progress through. On each Stage the number line varies to make the maths gradually harder. The higher the Stage, the more points you earn for each piñata smashed, enabling good players to rack up really high scores!

To move up through the Stages, you need to answer the maths problems correctly and consistently. The fewer errors you make, the faster you progress to the higher Stages and the more points you can make.

On the other hand, if you’re consistently wrong then you risk being relegated to a lower Stage – which is good for letting you practise and improve your maths skills, but not so good for your score!

If you’re a fantastic player then you might ‘loop’ the game, move past Stage 24 and return to the earlier Stages. When this happens the game becomes faster and tougher, so don’t get complacent! Each time you loop the game, an asterisk (*) appears after the Stage number.

#### Scoring

On each Stage the score for each piñata smashed is calculated as:

**Piñata Score = {Base Score + Stage Bonus × (Stage Number + 24 × Loop)} × Mode Multiplier**

- Base Score
- 50 points.
- Stage Bonus
- 20 points.
- Stage Number
- Number of the current Stage.
- Loop
- Number of times you have ‘looped’ the game, i.e. progressed beyond Stage 24 and returned to an earlier Stage.
- Mode Multiplier
- Factor that varies according to the Mode selected: Mode 1 = 1; Mode 2 = 2; Mode 3 = 3.

**Example 1:**
You play Mode 1 (Mode Multiplier = 1) and reach Stage 16 (Stage Number = 16), but have not looped the game (Loop = 0).

So your score for each piñata smashed = {50 + 20 × (16 + 24 × 0)} × 1 = 50 + 20 × 16 = 370 points.

**Example 2:**
You play Mode 3 (Mode Multiplier = 3) and reach Stage 8 (Stage Number = 8) having looped the game once (Loop = 1).

So your score for each piñata smashed = {50 + 20 × (8 + 24 × 1)} × 3 = {50 + 20 × 32} × 3 = 2,070 points.

After each game, your best score is recorded automatically.

### Improve your score

#### Basic Strategies

- Generally you should aim to smash the lowest piñatas first. However, if you’re starting to get swamped and running all over the place then it may be wise to sacrifice a piñata or two so you can catch your breath and plan a new strategy.
- If you have several piñatas descending together in a row, start at the left-most one and work your way right – this will mean you get easier maths.
- The fancier the gift box, the better the present inside. So if you have several gift boxes to choose from, go for the fanciest-looking one first.
- If a gift box starts flashing, that means it’s about to disappear. If you haven’t started moving yet to collect the box, probably best to forget it – unless you’re super-fast, chances are you won’t reach it before it disappears.

#### Maths Strategies

**Mode 1 Strategies**

**Solving the problems by counting the gap:**When solving a problem, you could start by looking at where your character is standing. Next, count how far it is to the piñata you want to smash or gift you want to grab. Your number line might be marked in 1s so count 1, 2, 3, 4, etc. But some number lines go in 2s or 5s so you might need to count 2, 4, 6, 8, etc, or 5, 10, 15, 20, etc. Once you work out how far your character has to travel, you know what size number you need to enter.**Solving problems by counting on:**When solving a problem, you may need to move your character to the right. This means counting on (adding) from the position you are standing at.

For example: -3 + ? = 5. You can solve this problem in your head by ‘counting on’. Start by counting on 3 more from -3 to give -3 + 3 = 0. This gets you to zero. Then think of counting on 5 more to give 0 + 5 = 5. So all together you added on 3 and 5 to give 8. So -3 + ? = 5 becomes -3 + 8 = 5.**Solving problems by counting back:**When solving a problem, you may need to move your character to the left. This means counting back (subtracting) from the position you are standing at.

For example: 4 - ? = -3. You can solve this problem in your head by ‘counting back’. Start by counting back 4 from 4 to give 4 - 4 = 0. This gets you to zero. Then think of counting back 3 more to give 0 - 3 = -3. So all together you subtracted 4 and 3 to give 7. So 4 - ? = -3 becomes 4 - 7 = -3.

**Mode 2 Strategies (Advanced)**

- In Mode 2 there are two ways to move your character to the left, that is, to perform a subtraction. For example: if you want to move from position 4 to position -3, you might have to solve this problem [4 - ? = -3] or this problem [4 + ? = -3].

To solve 4 - ? = -3 you need to know that you subtract 7 to get from 4 to -3. So the answer is 4 - 7 = -3. To solve 4 + ? = -3 you need to know that adding (-7) is the same thing as subtracting 7. So the answer is 4 + (-7) = -3.

**Mode 3 Strategies (Advanced)**

- In Mode 3 there are two ways to move your character to the right, that is, to perform an addition. For example: if you want to move from position -2 to position 3, you might have to solve this problem [-2 + ? = 3] or this problem [-2 - ? = 3].

To solve -2 + ? = 3 you need to know that you add 5 to get from -2 to 3. So the answer is -2 + 5 = 3. To solve -2 - ? = 3 you need to know that subtracting (-5) is the same thing as adding 5. So the answer is -2 - (-5) = 3.