Finding the whole from a pie chart

The pie chart shows the shells Priya collected at the beach. The cowrie shell part is marked with a right angle. How many shells did Priya collect altogether? How many scallop shells did she collect? Try it first. Pause if you like. From the chart, forty-five shells are cowrie shells, seventy-five are clam shells and thirty-six are snail shells. The total is not given. What does the small right-angle square tell us about the cowrie shells? The right angle shows that one quarter of the shells are cowrie shells. Follow the quarter-circle guide around the same circle. Four equal quarters make the whole. Each quarter represents the same number of shells. The total is forty-five times four, which equals one hundred and eighty. Priya collected one hundred and eighty shells altogether. To find scallop shells, subtract all three known kinds from the whole. Scallop shells: one hundred and eighty minus forty-five minus seventy-five minus thirty-six equals twenty-four. She collected twenty-four scallop shells. The marked quarter gave us the whole. Subtracting the other parts then gave the missing part.

The pie chart shows the packets of noodles of each flavour a shop sold in a week. Curry and tom yam together make one half of the chart. Chicken noodles are marked with a right angle. How many packets of mushroom noodles did the shop sell? Try it first. Pause if you like. From the chart, the shop sold one hundred and twenty curry packets and ninety-six chicken packets. One twelfth of the packets were prawn noodles. The right angle shows that the ninety-six packets of chicken noodles are one quarter of the packets. The chicken part is a quarter of this same whole circle. Watch four equal quarters fit around it. The total is ninety-six times four, which equals three hundred and eighty-four. The shop sold three hundred and eighty-four packets altogether. Curry and tom yam fill this half-circle together. The other half is the same size. We divide the whole by two. Curry and tom yam together: three hundred and eighty-four divided by two equals one hundred and ninety-two. Tom yam: one hundred and ninety-two minus one hundred and twenty equals seventy-two. Prawn: three hundred and eighty-four divided by twelve equals thirty-two. We now know every other flavour. Subtract each of those four counts from the total. Mushroom: three hundred and eighty-four minus one hundred and twenty minus seventy-two minus ninety-six minus thirty-two equals sixty-four. The shop sold sixty-four packets of mushroom noodles. Find the whole from the marked quarter first. Then find every missing part in order.