Question

It is expected that gas prices will rise to be 142% of the current amount. If the current gas price is $4 per gallon, explain how to estimate the expected price of gas

Answer 1

Explanation:

142% is about 140%. Using the distributive property, 140%($4) = 100%($4) + 40%($4) = $4 + $1.60. So, the price of gas is expected to be about $5.60 per gallon.

Answer 2

$5.68

Explanation:

142% of the current price of $4 per gallon is found by multiplying these numbers:

142% × $4.00/gal = $5.68/gal

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Of course, you know that 142% = 142/100 = 1.42. The numbers get multiplied and the units ($/gal) get applied to the result.

Multiplication by 4 is easily done mentally by doubling twice:

4×1.42 = 2×(2×1.42) = 2×2.84 = 5.68