2nd Grade Addition and Subtraction: Key Terms and Facts Every Student Should Know

The addition is one of the basic operations in math. It means combining two or more numbers to get a bigger number. For example, if you have 3 apples and 4 oranges, add them together to get 7 fruits.

The symbol for addition is +. To add two numbers, you must line them up according to their place values (ones, tens, hundreds, etc.) and then add each pair of digits from right to left. If a pair of digits sum is 10 or more, you must carry the extra digit to the next place value.

For example:

In this example, we start by adding the ones: 7 + 6 = 13. Since this is more than 10, we write 3 in the ones place and carry over 1 to the tens place.

Then we add the tens: 1 + 3 + 5 = 9. We write 9 in the tens place.

Finally, we add the hundreds: 2 + 4 = 6. We write 6 in the hundreds place.

The final answer is 693.

Subtraction is another basic operation in math. It means taking away one number from another number to get a smaller number. For example, if you have 7 candies and eat 4 of them, you can subtract them to find out how many candies you have left.

The symbol for subtraction is -. To subtract two numbers, you need to line them up according to their place values (ones, tens, hundreds, etc.) and then subtract each pair of digits from right to left. If the digit on the top is smaller than the digit on the bottom, you must borrow a digit from the next place value.

In this example, we start by subtracting the ones: 3 - 6 = -3. Since this is negative, we borrow a digit from the tens place and make it 13 - 6 = 7. We write 7 in the ones place and reduce the tens place by one.

Then we subtract the tens: 8 - 5 = 3. We write 3 in the tens place.

Finally, we subtract the hundreds: 5 - 4 = 1. We write 1 in the hundreds place.

The final answer is 237.

There are some words that you need to know for 2nd-grade math. These words help learners understand what the math problems ask them to do and how to explain their answers.

Here are some of the most common words:

• Addend: A number that is added to another number. For example, in 3 + 4 = 7, both 3 and 4 are addends.
• Sum: The answer to an addition problem. For example, in the addition sentence, 3 + 4 = 7; the number 7 is the sum.
• Minuend: A number that is subtracted from another number. For example, in the subtraction sentence, 7 - 4 = 3, the number 7 is the minuend.
• Subtrahend: A number that is subtracted from another number. For example, in 7 - 4 = 3, the number 4 is the subtrahend.
• Difference: The answer to a subtraction problem. For example, in the subtraction sentence, 7 - 4 = 3, the number 3 is the difference.
• Place value: The value of a digit depending on its position in a number. For example, in 237, the 2 has a place value of hundreds, the 3 has a place value of tens, and the number 7 has a place value of ones.
• Regrouping: The process of rearranging digits in a number to make adding or subtracting easier. For example, in 237 + 456, we can regroup 237 as 200 + 30 + 7 and 456 as 400 + 50 + 6. This makes it easier to add each pair of digits.

There are some facts or basic rules and strategies that you need to know for addition and subtraction. These facts help you do math faster and more accurately.

Here are some of the most important facts:

• The commutative property means that you can change the order of the addends without changing the answer.

For example, 3 + 4 = 4 + 3.

• The associative property means that you can change the grouping of the addends without changing the answer. For example, (3 + 4) + 5 = 3 + (4 + 5).
• The identity property means that adding zero or subtracting zero does not change the number. For example, 3 + 0 = 3 and 3 - 0 = 3.
• Inverse property means that adding the opposite or subtracting the same number gives zero. For example, 3 + (-3) = 0 and   3 - 3 = 0.
• Addition and subtraction facts: These are the basic combinations of numbers that you need to memorize. For example, you need to know that 2 + 2 = 4, 5 - 3 = 2, etc.

Knowing these facts will help you do math faster, mentally, and more confidently.