Rounding decimals is same as the rounding off numbers. For example a number 49 is rounded to 50. In the same way a
decimal number 0.49 is rounded to 0.50. Because here the tenths place is 4. The number after tenths place is 9 (which is > 5).
So round up, add 1 to 4 which becomes 5. Hence the answer is 0.50.
Example 1: Round the following decimal numbers to the nearest tenths place.
(a) 12.456 (b) 468.83
(a)12.456
Step 1: Tenths place value is 4
Step 2: Observe the next digit 5 (this is equal to 5). So round up the tenths place.
Step 3: Add 1 to 4 which equals to 5
12.456 When rounded to nearest tenths place = 12.5
(b) 468.89
Step 1: Tenths place value is 8
Step 2: Observe the next digit 3 (which is less than 5). So round down to the tenths place.
Step 3: So 8 remains the same.
468.89 When rounded to nearest tenths place = 468.8
Example 2: Isbella bought a dress which costs $ 46.15, a pair of shoes worth $15.60 and cosmetics of $20.28. About how
much money did Isbella spent in her shopping? Round of to nearest tenths place.
Cost of a dress = $46.15
When rounded off to nearest tenths place, it equals to $46.2
Cost of shoes = $ 15.60
When rounded off to nearest tenths place, it equals to $15.6
Cost of cosmetics = $ 20.18
When rounded off to nearest tenths place, it equals to $ 20.2
Total money spent = 46.2 + 15.6 + 20.2
= 82.0