Answer:
Yes, he is correct
Step-by-step explanation:
In the picture attached, the complete question is shown.
Richard instead of subtract 67 to 93 by subtracting successively 6 tens and 7 ones starting at point 93, which result in 26; he added 26 to 67, to do so he marked 67 on the line and then added 2 tens and 2 threes until he reached 93. Notice that 10 + 10 + 3 +3 = 26.
To check his work we make the following addition: 67 + 26 = 93, which is another way to write 93 - 67 = 26
