Add or subtract as indicated. 3.87 + 15 + 2.9

Verified step by step guidance

1. Identify the numbers to be added: 3.87, 15, and 2.9.
2. Align the numbers by their decimal points to ensure proper addition:
3. \[\begin{array}{r} 3.87 \\ 15.00 \\ +\ 2.90 \end{array}\]
4. Add the numbers starting from the rightmost decimal place (hundredths), then move to the tenths, and finally the whole numbers.
5. Combine the sums from each place value to write the final sum as a decimal number.

Key Concepts

Addition of Real Numbers

Addition of real numbers involves combining their values to find a total sum. When adding decimals and whole numbers, align the decimal points to ensure accurate calculation. The sum is the total amount obtained by adding all numbers together.

Decimal Place Value

Decimal place value refers to the position of digits to the right of the decimal point, representing tenths, hundredths, etc. Understanding place value is essential for correctly aligning numbers during addition or subtraction to maintain accuracy.

Order of Operations in Simple Arithmetic

In expressions involving only addition and subtraction, operations are performed from left to right. Recognizing this helps in correctly adding or subtracting numbers step-by-step without confusion.