Grade 4 - Progress in Mathematics

Add Decimals

13-8

Shawn walked 2.1 km in the morning

and 1.95 km in the afternoon.

How far did he walk altogether?

To find how far altogether, add:

2.1
1.95

First, round to estimate the sum:

2.1
1.95 2 
 2  4

Then add.

Line up the Add the Add the tenths. Add the

decimal points. hundredths. Regroup. ones.

1 1


 2 1 0 
 2 1 0 
 2 1 0 
 2 1 0


 1 9 5 
 1 9 5 
 1 9 5 
 1 9 5


 8.9 5 
 8.0 5 
 4 0 5

Remember:

2.1 2.10

Shawn walked 4.05 km altogether.

Study these examples.

1 1 1 1

0.8 5.7 5 7 5. 0 0


 0.6 0.9 0 
 6.4 2

1.4 
 2 8.3 2 8 1.4 2

3 4.9 7

2.1

1.95

Round to estimate the sum. Then add.

1. 
   0.3 2.
   1.4 3.
   0.9 4.
   5.6 5.
   8.5
   
   0.6
   6.2
   0.7
   9.8
   10.5


2. 
   0.12 7.
   3.01 8.
   0.84 9.
   $ 2.9 0 10.
   4.5 5
   
   0.43
   0.57
   0.77
   7.83
   2.86

Think

4.05 is close to 4.

The answer is reasonable.

Write the decimal point

in the sum.

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