What is 15% of 640?

There are different ways to approach this question: directly or breaking it down.By using the method of breaking it down, we can split this percentage into easier percentages. 15% is the sum of 10% and 5%, where 5% is half of 10%. We can calculate 10% knowing that 10% is equivalent to 10/100th, which simplifies to 1/10th. Since we know 1/10th of a number is the same as dividing that number by 10, we can calculate 1/10th of 640 by doing 640 divided by 10, which is 64. As we said earlier, 5% is half of 10%, and since 10% of 640 was 64, 5% would be 32. Going back to stating that 15% = 10% + 5%, we can say that 15% of 640 would be equal to 64 + 32 = 92.A more direct method, which may work better for harder percentages to break down, is by realising that % means /100, so 15% is 15/100, which we can convert to a decimal (0.15) and multiply 0.15 by 64 straight away, giving 92.