Question

It say estimate each problem to check if the students answer is reasonable. If not , Cross out the answer and write the correct answer. Show Your Work

Answer 1

2)
`-3(1)/(6) + 6(2)/(3)` : given answer
`-3(1)/(2)` is incorrect

Step by step explanation:

Step 1:

Split the question as,

`-3 - (1)/(6) + 6 + (2)/(3)`

Step 2:

Add whole number and fractions individually, it becomes

`6 - 3 + (2)/(3) - (1)/(6)`

=
`3 + (12)/(18) - (3)/(18)`

=
`3+(1)/(2)`

can be written as
`3(1)/(2)` (correct answer)

3) -4.2 - (-2.9) : given answer - 1.3 is correct

calculated as

- 4.2 + 2.9 = - 1.3

4)
`3(1)/(5) - 2(1)/(2) + 2(3)/(5)` : given answer
`-3(1)/(3)` is incorrect

Step by step explanation:

Step 1:

Split the question as,

`3 + (1)/(5) - 2 - (1)/(2) + 2 +(3)/(5) \\`

Step 2:

Add whole number and fractions individually, it becomes

`3 + (3)/(5) +(1)/(5)- (1)/(2)`

=
`3 + (4)/(5) - (1)/(2)`

=
`3 + (8)/(10) - (5)/(10)`

=
`3 + (3)/(10)`

can be written as
`3(3)/(10)` (correct answer)