Hi! I was not sure if you were able to use a calculator so i wrote down every step. From there, you can see my thought process. Q5a and 7 (refer to 2nd pic for solution) are pretty similar, simply cross multiply the numbers. For Q5a, I stroked out 16 (replaced it with 8) and 2 (replaced it with 1) because 16 and 2 were divisible by 2. Similarly, i cancelled 9 (replaced it with 3) and 3 (replaced it with 1) because 9 and 3 were both divisible by 3. Then, multiply the new numerators together and do the same for the new denominators to arrive at the answer. Apply the same method for Q7.

As for 5b, i changed the proper fraction to an improper fraction first so that it is easier to cross multiply. After changing, i applied the same method used in 5a to solve, then i changed the product back to a proper fraction.

For 6, the question said to find the 'sum' (which means '+'/ addition) of 3/10 and the 'difference' (which means '-'/ subtraction) between the other two numbers. 'Translate' whatever you read into MATH. It will be as written on the piece of paper.
Hope this helps you!

Here's Q7! Refer to the first answer for comments:))