Final answer:
To find the unknown number B in the equation 12 x B = 480, we can use mental math to divide 480 by 6 and then divide the result by 2, which gives us the answer of 40.
Step-by-step explanation:
Algebra: Using Mental Math to Find the Unknown Number
To find the unknown number in the equation 12 x B = 480, we can use mental math. First, we notice that 12 is a multiple of 2 and 6, so let's start by dividing 480 by 6. This gives us 80. Now, we divide 80 by 2, which gives us 40. Therefore, the unknown number B is 40.
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