Multiplication Of Whole Number

Back to: Mathematics Primary 3

Multiplication is the process of calculating the total of one number multiplied by another. Multiplying means repeated addition of a number. (The number must all be the same before we can use it to multiply.)

When you think of it this way, learning the Times Tables makes sense.

Let’s take the 3 times tables, for example.  Students usually learn the 3 times tables this way:

1 x 3 = 3

2 x 3 = 6

3 x 3 = 9

and so on.

Using the idea of groups, we have:

1 x 3 = 3 (1 group of 3)

2 x 3 = 3 + 3 = 6 (2 groups of 3)

3 x 3 = 3 + 3 + 3 = 9 (3 groups of 3) and so on.

So if your child knows the answer to 3 x 4 is 12, but cannot remember the answer to
4 x 4, they will just need to add 4 to 12 to get the answer.

4 x 4 = 12 + 4

Now let’s look at something interesting:

3 groups of 5 = 5 + 5 + 5 = 15

5 groups of 3 = 3 + 3 + 3 + 3 + 3 = 15

3 groups of 5 has the same answer as 5 groups of 3!

So, 3 x 5 = 5 x 3

This means that when you multiply 2 numbers, the order of the numbers (which number is first and which is second) does not matter, the answer will still be the same.

Multiplication of 3 digit by 1 digit

Quiz

 

2. Find the product of 342 and 2.
3. 35 x 2

Solve these

1. A photogragh of a plant that that is 42 millimetres long is enlarged 4 times for a science book. Estimate how long the plant is in the book.
2. Daniel returned from her visit to the United States with $100. On the day she arrived, one United States dollar could be exchanged for 4 Nigerian naira. How many Naira would she receive for the $100?

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