<span>It is a weak negative correlation, and it is not likely causal.</span>
<span> Compatible numbers are numbers that look nice or friendly with each other when we do mental calculation to estimate a product, but especially a division</span>
Fifth grade has 24 students per each teacher.
Sixth grade has about 23 students per teacher.
Sixth grade is lower.
7 = 2n - 2
n= a number so twice a number is 2n and 7 is 2 less than twice this number.
