Question

Maddy's fourth grade class is going on 5 field trips. Each has a fee of $12.10. Sack lunches for each trip are an additional $2.75. Round each amount to the nearest dollar to find an estimate for the cost of all 5 trips.

Answer 1

Let x=0.47ˉ  (Mixed recurring decimal)

i.e. x=0.47777…(1)

Multiplying (1) by 10, to make it pure recurring decimal, we get

10x=4.7777…(2)

Further multiplying (2) by 10, we get

100x=47.777….(3)

Subtracting (2) from (3), we get

100x–10x=(47.777…)–(4.7777…)

⇒90x=43

⇒x=9043

Thus 0.47ˉ=9043