Question

cam tries to find $3 \times 105$.
in which step does cam make the first error?
step 1
step 2
step 3
step 4
cam’s work
image of a rectangle divided into two parts, with left part labeled 10 (top), 3 (left), 30 (middle); right part labeled 5 (top), 15 (middle), 3 (left)
step 1: $105 = 10 + 5$
step 2: $3 \times 10 = 30$, and $3 \times 5 = 15$
step 3: $30 + 15 = 45$
step 4: $3 \times 105 = 45$

Explanation:

Step1: Analyze Step 1

Check if \(105 = 10 + 5\). But \(10 + 5 = 15
eq105\). The correct decomposition should be \(105 = 100+5\) (or using place - value correctly). So Step 1 has an error.

Step2: Verify other steps (optional)

Even though Step 2's multiplications (\(3\times10 = 30\), \(3\times5 = 15\)) are correct in isolation, the error starts in Step 1 because the decomposition of 105 is wrong.

Answer:

Step 1