Estimation is a important skill to know when adding and subtracting decimals because if you estimate you have an idea on what your answer should be close to.
For example 4.68-2.38 could be 5-2 which is 3. 4.68-2.38 equals 2.3. 2.3 is close to 3.
16 students is the correct answer...
for every 5 boys there are 3 girls, so 20 boys 6 girls = the total of 16 students
