Question

solution
4 anders adds 8.84 and 62.5, but he makes an error in his work. describe his mistake and show the correct addition.
anders
¹
8.84
+ 62.5
150.9

the length of a lap on a running track depends on the lane.
greg runs one lap in lane 4, one lap in lane 5, and one lap in lane 6. what is the total distance greg runs? show your work.

tion
son 7 add, subtract, and multiply multi - digit decimals
©curriculum associates, llc

Explanation:

Step1: Identify the Mistake

When adding decimals, we need to align the decimal points (or the place values). Anders did not align the decimal points correctly. He added \(8.84\) and \(62.5\) as if \(8.84\) was \(88.4\) (by misaligning the digits, probably adding the units place of \(8.84\) to the tens place of \(62.5\)).

Step2: Correct Addition

To add \(8.84\) and \(62.5\) correctly, we align the decimal points:

$$
LATEXBLOCK0
$$

Now, add the numbers:

• The hundredths place: \(4 + 0 = 4\)
• The tenths place: \(8 + 5 = 13\), carry over \(1\) to the ones place, write \(3\) in the tenths place.
• The ones place: \(8 + 2 + 1 = 11\), carry over \(1\) to the tens place, write \(1\) in the ones place.
• The tens place: \(0 + 6 + 1 = 7\)

So the correct sum is \(71.34\).

Answer:

Anders' mistake was not aligning the decimal points (or place values) correctly when adding. The correct addition is \(8.84 + 62.5 = 71.34\) (shown by aligning decimals: \(

$$\begin{align*}&\ \ \ 8.84\\+&62.50\\\hline&71.34\end{align*}$$

\)).