Video Transcript
A primary school has 64 classes with 58 students in each class. Calculate the total number of students. Round your answer to the nearest hundred.
To find the answer, we’ll need to multiply the number of classes by the number of students in each class: 64 times 58. We’ll start with the number in the ones place and we’ll multiply eight times four. Eight times four is 32. We write down our two and carry the three.
Next, we multiply eight by six. Eight times six is 48. But we can’t forget the three that we carried over. This means we have 49, 50, 51. So we took eight times six, which is 48, and we added three to equal 51.
Our first row is then 512. We added the three. So we’re gonna cross it out. And then, we’ll move on to our tens place and multiply five times four. Five times four is 20. So we need to bring down our zero and write our two above the six.
Remember that when we’re multiplying two digit numbers and we work with the tens place — in this case, our five — we have to leave the ones place empty, where this pink square is. Next, we’ll multiply five times six. Five times six is 30 plus the two, which is 32. And we bring down the 32. We’re now finished with the multiplication step and we need to add. Two plus zero is two, one plus zero is one, five plus two is seven, and three plus zero is three.
The first step of our problem told us to calculate the number of students. The total number of students is 3712. The second step of the question though asks us to round the answer to the nearest hundred. So we must round 3712 to the nearest hundred. We have a seven in our hundredths place and a one in our tens place.
Remember when we’re rounding, we always look to the right to see how should we round our place value. This one is less than five. That means we’re going to round down. Our seven stays the same and everything to the right of the seven becomes a zero.
The number of students rounded to the nearest hundred is 3700. There were approximately 3700 students at this primary school.
