Irene makes a second batch of 3 and 1/4 cups of pancake batter. she wants to know how much more batter she made in the first batch. she estimates that the difference between the sizes of the two batches 4 and 2/3 - 3 and 1/4 is 2 and 1/12. explain why this estimate is not reasonable.

The estimate is not reasonable because

4 2/3 is equivalent to 4 8 /12 ,

and 3 1/4 is equivalent to 3 3/12,

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.