Question

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Part 1
Scientists often use a pan balance to measure mass when doing experiments. The equation 7 plus 3 plus 2 equals 10 plus 2 represents when a scientist adds 2 units of mass to each side of a pan balance. Construct an argument to explain how the scientist knows that the pans are still in balance.
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Part 1
▼
A larger
A smaller
The same
amount of mass was
▼
added to
removed from

▼
both pans,
the left pan,
the right pan,
so the mass in the pans
▼
remains equal
is now unequal
and the pans stay in balance.

Answer 1

The same amount of mass was added to both pans, so the mass in the pans remains equal and the pans stay in balance.

Explanation: 7 + 3 = 10, and adding 2 to each side gives 7 + 3 + 2 = 10 + 2 (12 = 12). Adding the same mass to both sides does not change the equality.