Ana completed 40% of her homework assignment. Her assignment contains 30 math problems. How many problems does anna. still need to complete?

What you have to do, is multiply 40% and 30 (being the total number of math problems) First, change the 40% to a decimal by moving it from the percent sign two times to the left. Making it. 40 Multiply those together and you should get 12. Ana has 12 problems left.