There are 4 basic operations in math: addition, subtraction, multiplication, and division.
Let's review what you've learned about them so far.
Addition is putting together two or more numbers.
An addend is a number that's added to other numbers.
The plus sign + is what tells us that we need to add.
The equal sign = tells us that the value on the left side is equal to the value on the right side.
The sum is the number we get when add numbers.
Let's try adding some numbers.
6,034 + 2,841 = ?
Let's add the numbers using column form, starting from the Ones place:
What's our answer? 😃
That's right! It is 8,875.
6,034 + 2,841 = 8,875
Great work!
356 + 297 = ?
Let's add!
This time we need to do regrouping.
Regrouping is taking 10 from one place value and giving it to the next higher place value.
Our sum is 653. ✅
Awesome! 😎
Now, let's move on to subtraction.
Subtraction is taking away a part of a number.
The minuend is the number we're subtracting from.
The subtrahend is the number that's being subtracted.
The minus sign tells us to subtract.
The difference is the answer we get when subtracting.
Memorization tip:
Let's try subtracting some numbers. 🤗
9,586 - 3,172 = ?
Let's subtract the numbers using the column form.
Start subtracting from the Ones place.
What's the difference, or answer? 🤓
9,586 - 3,172 = 6,414
Nice work! 👏
512 - 243 = ?
Let's subtract!
Remember to start subtracting from the Ones place.
We need subtract 3 from 2.
3 is larger than 2, so we can't subtract right away. 😕
We need to regroup one Ten into ten Ones!
Notice that we had to regroup in the Tens place also.
Way to go! 🤗
Let's now review multiplication and division.
Multiplication is adding the same number over and over.
For example:
5 × 2 = 10
This means that 5 groups of 2 circles makes 10 circles in all.
A multiplication equation has these parts:
The multiplier and multiplicand are also called factors. These are the numbers we multiply together.
The multiplication sign tells us to multiply. It's read as "times".
The product is the answer we get.
Let's try to multiply.
7 × 6 = ?
You can multiply numbers using repeated addition.
✅ We can add 7 to itself 6 times, or add 6 to itself 7 times.
7 × 6 = 7 + 7 + 7 + 7 + 7 + 7 = 42
So,
7 × 6 = 42
Great work!
Multiplication is so important, you should have your multiplication tables memorized by now! If not, got back to our 3rd grade multiplication lessons.
268 × 4 = ?
Let's try multiplying these numbers using column form.
🔸 First, we multiply the digit at the Ones place by 4.
🔸 Next, we multiply the digit at the Tens place by 4, and add the number we carried over.
🔸 Lastly, we multiply the digit at the Hundreds place by 4, and add the number we carried over.
What answer did you get?
268 × 4 = 1,072
Nice job! 👏
Division is splitting a number into equal groups.
For example, when we split 10 circles into 5 equal groups, we get 2 circles in each group.
10 ÷ 5 = 2
A division equation is made up of these parts:
Let's now look at some division examples.
30 ÷ 6 = ?
We can solve this division problem using repeated subtraction.
✅ We start at 30 and subtract 6 over and over again. We stop when we reach 0.
The number of times we subtracted is our answer.
How many times did you subtract?
Correct! 5 times.
So,
30 ÷ 6 = 5
Perfect! 🤗
Tip: It's even easier to think about division as the opposite of multiplication.
Just think this... 🤔
What number times 6 equals 30?
6 x ? = 30
And you get the same answer: 5! ✔️
944 ÷ 8 = ?
Let's solve this question using long division.
🔸 We start by arranging the numbers in long division form.
We work on the digits one at a time.
🔸 Now, look at the first digit.
Can you tell how many 8's fit into the 9? 🤔
Very good! 1.
Write the 1 on top, as the quotient.
🔸 Write the product of 1 and 8 below the digit 9.
Now, subtract 8 from 9.
Fantastic! 😎
🔸 Next, bring down the next digit and repeat the process.
🔸 Finally, bring down the last digit and repeat the process.
What answer did you get?
944 ÷ 8 = 118
The answer is exactly 118. No left-overs, or remainders.
Great job! 👏
1,492 ÷ 6 = ?
🔸 Let's write it in long division form.
🔸 Look at the first digit, 1.
We divide it with our divisor.
1 ÷ 6 = ?
We're dividing a smaller number by a bigger number.
So our answer is 0.
Let's write 0 on top, as the quotient.
Write the product of 0 and 6 below 1.
Subtract 0 from 1.
Great job! 🤗
Here's an important tip: Don't skip dividing the first digit, even if it's smaller than the divisor. Work on the numbers one at a time, so you won't get confused.
🔸 Now bring down the second digit. Then just repeat the same process.
🔸 Bring down the third digit. Then do the same steps again.
🔸 Now, bring down the last digit and follow the same steps.
We've reached the last digit, yet there's still a number that's left over.
This number is our remainder.
We write it at the top with an "r" or "R".
When we write the answer, we disregard the zero at the beginning of the quotient.
1,492 ÷ 6 = 248 r4
Great work! 😀
🎉 You've just reviewed the most important points about addition, subtraction, multiplication and division. 😅
Now, start the practice. 😀 It'll help you remember for longer.