When you are putting values into math expressions, there are some common mistakes you should try to avoid. Here’s a simple list to help you remember:
Forget the Order of Operations: Always follow the BIDMAS/BODMAS rule. This stands for Brackets, Indices, Division and Multiplication, Addition, and Subtraction. For example, in the expression (3 + 2 \times x) where (x=4), you should first do the multiplication: (2 \times 4 = 8). Then, you add (3) to get (11). If you add first, you might think the answer is (20), which is wrong.
Getting Negative Signs Wrong: Be careful with negative signs when you substitute values. For example, in the expression (-a + b) where (a = 3) and (b = 5), calculate (-3 + 5). You will end up with (2), not (-8).
Using the Wrong Values: Always check that you have the right values before substituting. If you have the expression (2x + y) and you say (x=2) but mistakenly remember (y=3) instead of (y=5), your answer will be wrong. You would calculate (4 + 3 = 7) instead of getting the correct answer (4 + 5 = 9).
Not Replacing All Instances: Make sure to replace every instance of the variable. If your expression is (2x + 3x) and you substitute (x=2), do this for both parts. It should look like (2(2) + 3(2) = 4 + 6), which equals (10).
By keeping these tips in mind, you can avoid mistakes and get the right answers in your math expressions!
When you are putting values into math expressions, there are some common mistakes you should try to avoid. Here’s a simple list to help you remember:
Forget the Order of Operations: Always follow the BIDMAS/BODMAS rule. This stands for Brackets, Indices, Division and Multiplication, Addition, and Subtraction. For example, in the expression (3 + 2 \times x) where (x=4), you should first do the multiplication: (2 \times 4 = 8). Then, you add (3) to get (11). If you add first, you might think the answer is (20), which is wrong.
Getting Negative Signs Wrong: Be careful with negative signs when you substitute values. For example, in the expression (-a + b) where (a = 3) and (b = 5), calculate (-3 + 5). You will end up with (2), not (-8).
Using the Wrong Values: Always check that you have the right values before substituting. If you have the expression (2x + y) and you say (x=2) but mistakenly remember (y=3) instead of (y=5), your answer will be wrong. You would calculate (4 + 3 = 7) instead of getting the correct answer (4 + 5 = 9).
Not Replacing All Instances: Make sure to replace every instance of the variable. If your expression is (2x + 3x) and you substitute (x=2), do this for both parts. It should look like (2(2) + 3(2) = 4 + 6), which equals (10).
By keeping these tips in mind, you can avoid mistakes and get the right answers in your math expressions!