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Multiplication - Multiplication Tables 2 to 10

Grade 3ICSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

Multiplication is the process of Repeated Addition. For example, 3×43 \times 4 means adding 44 three times: 4+4+4=124 + 4 + 4 = 12. Visually, this can be seen as 33 rows of 44 dots each forming a rectangular grid totaling 1212 dots.

Terminology: In a multiplication sentence like 5×2=105 \times 2 = 10, the number being multiplied (55) is the Multiplicand, the number of times it is multiplied (22) is the Multiplier, and the result (1010) is the Product.

Order Property (Commutative Property): Changing the order of the numbers does not change the product. For example, 4×5=204 \times 5 = 20 and 5×4=205 \times 4 = 20. Visually, a grid of 44 rows and 55 columns is simply a rotated version of a grid with 55 rows and 44 columns.

The Identity Property of One: Any number multiplied by 11 stays the same (6×1=66 \times 1 = 6). Visually, this is like having one single group containing 66 items.

The Zero Property: Any number multiplied by 00 results in 00 (9×0=09 \times 0 = 0). Visually, this represents having multiple groups (like 99 boxes) but with nothing inside them, resulting in a total of zero.

Multiplication on a Number Line: Multiplication can be visualized as taking equal-sized jumps. To solve 3×23 \times 2, you start at 00 and take 33 jumps of 22 units each, landing on 2,4,2, 4, and finally 66.

Patterns in Tables: Specific tables have recognizable patterns. For example, the table of 55 always ends in the digits 00 or 55 (5,10,15,20...5, 10, 15, 20...), and the table of 1010 always ends in 00 (10,20,30...10, 20, 30...).

Doubling and Halving: Knowing the table of 22 helps with the table of 44. Since 44 is double of 22, the results in the table of 44 are double the results in the table of 22. For example, 2×3=62 \times 3 = 6, so 4×3=124 \times 3 = 12.

📐Formulae

Multiplicand×Multiplier=Product\text{Multiplicand} \times \text{Multiplier} = \text{Product}

a×b=b×aa \times b = b \times a (Commutative Property)

a×1=aa \times 1 = a (Identity Property)

a×0=0a \times 0 = 0 (Zero Property)

Total=Number of Groups×Items per Group\text{Total} = \text{Number of Groups} \times \text{Items per Group}

💡Examples

Problem 1:

Calculate the total number of legs on 88 spiders, if each spider has 88 legs.

Solution:

Step 1: Identify the number of groups. There are 88 spiders. \ Step 2: Identify the number of items per group. Each spider has 88 legs. \ Step 3: Set up the multiplication: 8×88 \times 8. \ Step 4: Use the table of 88: 8,16,24,32,40,48,56,648, 16, 24, 32, 40, 48, 56, 64. \ Step 5: The product is 6464.

Explanation:

Since there are equal groups of legs, we multiply the number of spiders by the number of legs per spider.

Problem 2:

Find the missing number: 7×6=6×?7 \times 6 = 6 \times \text{?}

Solution:

Step 1: Recall the Commutative Property of multiplication, which states a×b=b×aa \times b = b \times a. \ Step 2: In the expression 7×67 \times 6, the factors are 77 and 66. \ Step 3: To keep the product the same when 66 is written first, the second factor must be 77. \ Step 4: 7×6=427 \times 6 = 42 and 6×7=426 \times 7 = 42. \ The missing number is 77.

Explanation:

This example demonstrates that the order of numbers in multiplication does not change the final result.