Ethan used compensation to find the sum of 27 + 38. What number is missing from his work?

See explanation

Step-by-step explanation:

Given

Required

What number is missing in the workings?

The steps is not given. So, I'll solve from scratch

Using compensation to add numbers, we add an imaginary number to one of the number being added.

The aim of this imaginary number is to round up the digit to a multiple of 10.

So:

becomes

In this case the added number is (2) ... Note that this (2) will be subtracted after the addition has been completed

=  

Subtract the added (2)

Hence:

So, the missing number in Ethan's workings could have been 2

first anwser choice.

step-by-step explanation:

the greater/less or equal to symbol (> or < with the line at the bottom) is a closed/filled in circle.

-5c + 2 _< _27

subtract from both sides by 2

-5c _< _ 27

divide both sides by -5

c _< _ 5.4

flip the inequality sign

c _> _5.4

the only possible answer that would match the simplified inequality is the first answer choice

15%

step-by-step explanation:

use the table and count the number of guesses that has two correct answers.

the following are two correct answers

10010, 01100, 11000

a total of 3 numbers having 2 correct guesses out of 20 questions.

probability of getting 2 correct guesses = the number of questions getting 2 correct answers / total number of questions.

= 3/20

to convert it into percent multiply by 100, we get

= 3/20 * 100

= 15%

the answer is 15%

you.