# Video: KS2-M16 • Paper 2 • Question 11

Maria has a packet that contains 1.5 kg of oats. Every day, she uses 50 g of oats to make porridge. How many days does the packet of oats last?

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### Video Transcript

Maria has a packet that contains 1.5 kilograms of oats. Every day, she uses 50 grams of oats to make porridge. How many days does the packet of oats last?

Maria’s packet contains 1.5 kilograms of oats. And every day, she uses 50 grams of oats to make porridge. We need to work out how many days the packet of oats will last. So we already know that Maria eats 50 grams of oats daily. The question is asking us how many of these bowls can she make from one packet?

We know that one kilogram is equal to 1000 grams. 1.5 kilograms or one and a half kilograms is equal to 1500 grams. To calculate how many bowls of porridge Maria can make, we need to divide the total amount of oats, which is 1500 grams, by 50 grams, which is the amount of one bowl. We can use the inverse to help.

What do we multiply 50 by to get 1500? 50 times three is 150. We can use this fact to help us calculate 50 times 30, which is 1500. 30 is 10 times more than three. 1500 is 10 times more than 150. 50 times 30 is 1500. So 1500 divided by 50 equals 30. Maria’s packet of oats will last for 30 days.

To calculate the answer, first we converted the kilograms into grams. We wrote down the calculation, 1500 divided by 50. We calculated the answer using the inverse. We knew that 50 multiplied by three was 150. And we used this fact to find 50 multiplied by 30, which was 1500. We used the inverse to give our answer. 1500 divided by 50 equals 30. Maria’s packet of oats will last for 30 days.