Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Multiplication as Repeated Addition: Multiplication is a faster way of adding the same number multiple times. For example, if you see 4 baskets with 3 apples in each, you can visualize this as , which is the same as .
The Multiplication Sign (): The symbol is used to show multiplication. In the expression , the first number usually tells us the number of groups, and the second number tells us the items in each group. Visually, this looks like 5 pairs of socks laid out in a row.
Multiplication on a Number Line: You can find the product of two numbers by taking equal-sized jumps on a horizontal number line starting from . For , you would visualize big leaps of units each ( to , to , and to ), finally landing on the answer .
Rows and Columns (Arrays): Objects arranged in rows and columns form an array. If you have rows of stars with stars in each row, you can see a rectangular grid. The total number of stars is calculated as .
Skip Counting: Multiplication is closely related to skip counting. To solve , you can skip count by s four times: . Each count represents adding one more group of .
Order Property (Commutativity): Changing the order of numbers does not change the product. For instance, groups of dots () result in the same total as groups of dots (). Both equal .
Multiplying by Zero and One: When you multiply any number by , the answer is the number itself (e.g., ). When you multiply any number by , the answer is always (e.g., ), which is like having empty bags with nothing inside.
📐Formulae
💡Examples
Problem 1:
There are flower pots. Each pot has flowers. How many flowers are there in total?
Solution:
- Identify the number of groups: pots.
- Identify the number of items per group: flowers.
- Write as repeated addition: .
- Write as multiplication: . Total flowers = .
Explanation:
We use the concept of '5 times 4'. By adding the number 4 five times, we find the total sum.
Problem 2:
Convert the following addition into a multiplication fact: .
Solution:
- Count how many times the number is being added: It appears times.
- The number being added is .
- Multiplication fact: .
Explanation:
Since 7 is repeated 3 times, we represent this as '3 times 7', which is written as .