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How to do mental math for 23.7+1.95+2.3

User Windo
by
7.8k points

2 Answers

3 votes
1. Set up the long addition.

2 3 . 7 0
1 . 9 5
2 . 3 0
_________


2. Calculate 0 + 5 + 0, which is 5.

2 3 . 7 0
1 . 9 5
2 . 3 0
_________
5

3. Calculate 7 + 9 + 3, which is 19.
Since 19 is two-digit, we carry the first digit 1 to the next column.
1
2 3 . 7 0
1 . 9 5
2 . 3 0
_________
9 5

4. Calculate 3 + 1 + 2, which is 6. Now add the carry digit of 1, which is 7.


1
2 3 . 7 0
1 . 9 5
2 . 3 0
_________
7 . 9 5

5. Calculate 2 + 0 + 0, which is 2.

1
2 3 . 7 0
1 . 9 5
2 . 3 0
_________
2 7 . 9 5

6. Therefore, 23.7 + 1.95 + 2.3 = 27.95

27.95
User Masashi M
by
7.5k points
5 votes
First add these because they can make a whole number (they end in 7 and 3 which makes 10=1) 23.7+2.3=25.10=26 Now add 1.95. 26+1.95=27.95
User Leeroy Hannigan
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7.1k points