Idea 14of 23Builds onDecimals live between whole numbers
Rounding picks the closer tenth
What does it mean to round 1.84 to the nearest tenth?
Today you'll discover
- which two tenths 1.84 sits between
- how to tell which one is closer
- why rounding is not always up
Think first1.84 between 1.8 and 1.9
Is 1.84 closer to 1.8 or to 1.9?
Decide first, then press Next. Look at which end of the line the dot is nearer.
A number line from 1.8 to 1.9 with a mark for every hundredth and a dot at 1.84. Brackets show 4 hundredths back to 1.8 and 6 hundredths on to 1.9. An arrow moves the dot to 1.8, which is ringed: 1.84 rounds to 1.8. Then 1.87 rounds to 1.9. The last step shows 2.66.
See the whole ideathe big idea and the key word, in one place
The big idea
Rounding to the nearest tenth picks whichever neighbouring tenth is closer.
Two neighbours, one winner
1.84 sits between 1.8 and 1.9. It is 4 hundredths from 1.8 and 6 from 1.9, so it rounds to 1.8.
- To 1.84 hundredths
- To 1.96 hundredths
Compare themA rounded number is close, not exact. 1.8 is a shorter name for “about 1.84”.
Key words
- round
- replace a number with a simpler one close to it
- nearest tenth
- the tenth (like 1.8 or 1.9) that is closest to the number
- neighbour
- one of the two tenths (or wholes) just below and just above a number
Ready to use it?
- Pick which tenth a decimal is closer to.
- Round a decimal to the nearest tenth.