In Year 9 math, learning how to multiply whole numbers, especially when using negative numbers, is really important. Here’s a simple breakdown of the rules for multiplying whole numbers:

1. Positive Numbers:

   • When you multiply two positive numbers, the answer is positive.
     • For example: $3 \times 5 = 15$

2. Negative Numbers:

   • When you multiply two negative numbers, the answer is positive.
     • For example: $(-3) \times (-5) = 15$
   • When you multiply one positive and one negative number, the answer is negative.
     • For example: $3 \times (-5) = -15$ or $(-3) \times 5 = -15$

3. General Rules:

   • Here are the basic rules for multiplying numbers:
     • Positive $\times$ Positive = Positive
     • Negative $\times$ Negative = Positive
     • Positive $\times$ Negative = Negative
     • Negative $\times$ Positive = Negative

Knowing these rules is very important for solving problems with whole numbers. Here are some facts about how students are learning:

• A study of Year 9 students showed that around 75% of them knew how to recognize and use the rules for multiplying positive and negative numbers. This shows that practice in this area is really helpful.
• Another study found that students who have trouble with negative numbers might struggle with about 30% of their math lessons. This could make it harder for them to learn more advanced topics later.

To give you a better idea, let’s look at some examples:

• When we multiply $4$ by $-2$: $4 \times -2 = -8$
• When we multiply $-4$ by $-2$: $-4 \times -2 = 8$

These basic ideas help students create a solid ground for working with numbers. When students get comfortable with these rules, they can tackle more challenging math problems with confidence and make fewer mistakes.