Question Video: Writing the Decimal Numbers Marked on a Number Line Mathematics • 4th Grade

What decimals are marked on the number line?

04:17

Video Transcript

What decimals are marked on the number line?

On our number line, we’re given three labels 29.3, 30.3, 31.3. From 29.3 to 30.3 is a space of one unit. 29.3 plus one equals 30.3. Our next question will be: how many spaces is this one unit broken into? One, two, three, four, five, six, seven, eight, nine, 10. So we have one divided by 10. One divided by 10 equals 0.1. Every line on this number line is an increase of 0.1.

From 29.3 to our first missing number is an increase of 0.6. To find the missing number, we take 29.3 and add the 0.6 increase. 0.3 plus 0.6 equals 0.9. Nine plus zero equals nine. And two plus zero equals two. The first missing number is 29.9. We can use this information to find the second missing number.

Starting at 29.9, we’re moving forward one, two, three times. From 29.9, we’re moving forward 0.3. To find the number, we add 0.3 to 29.9. Nine plus three equals 12. We write down our two and carry our one. Bring down the decimal. In the units place, we add one plus nine plus zero which equals 10. We write down our zero and carry our one. In the tens place, we add one plus two which equals three, for a final answer of 30.2.

We’re still missing two values. To find the third missing number, we can start at 30.3 and then move forward one, two, three, four, five times. 30.3 plus 0.5 will give us the next missing value. Three plus five equals eight. Bring down the decimal. Zero plus zero equals zero. And three plus zero equals three, for a final answer of 30.8.

Our last missing value is to the right one, two, three places. So we start with our number 30.8 and then we add the 0.3 we moved to the right. 30.8 plus 0.3. Eight plus three equals 11. Write down your one and carry your one. Bring down the decimal. In the ones place, one plus zero plus zero equals one. And three plus zero equals three, for a total of 31.1. Our final marked place on this number line is 31.1.

In order from left to right, our missing values are 29.9, 30.2, 30.8, and 31.1.