Video Transcript
Find the number that, when multiplied by 10, results in 80.
This question describes a missing number problem in words. But we can also write it as a number sentence. Find the number that, when multiplied by 10, results in 80. What times 10 equals 80? Another way of saying the same problem might be, how many tens are there in 80?
We know that one multiplied by 10 equals 10. And we can carry on counting in tens until we get to 80. Two times 10 equals 20. Three multiplied by 10 equals 30. We can see a pattern in our answers. The number that we’re multiplying by 10 moves one place to the left. And so four multiplied by 10 becomes 40. Five multiplied by 10 equals 50. And so what number multiplied by 10 equals 80?
We can see that eight multiplied by 10 gives the answer of 80 that we’re looking for. The digit eight moves to the tens place. And we write a zero where it was in the ones place. 10, 20, 30, 40, 50, 60, 70, 80. There are eight tens in 80. The number that, when multiplied by 10, results in 80 is eight.
