4/1*2/3=simple multiplcation. numerator times numerator and denom. times denom. Then simplify or change to mixed fraction.
1/2 times 16 is basically 16/2. 16*1/2
For the Practise questions, any number 5 or greater-->round up 1
any number 4 or less-->stays the same.
EX: 4.67-->5, cuz .6 is greater than 5.
EX: 3,26-->3, cuz 2 is less than 6
Keeping that in mind will help you easily estimate those answers without doing a lot of thinking:)
