Student edition ← Addition and subtraction of decimals

Addition and subtraction of decimals

Advanced Math 4 · Unit 13 · decimal-add-sub · Teacher edition

decimal-add-sub

Name ______________________________Date ______________

1.
Compute $6.25 + 3.9$ .
Answer: ______________
2.
Jo has $20. She buys a book for $13.45 and a pen for $2.80. How much money does she have left, in dollars?
Answer: ______________
3.
A jug holds $5.2$ L of water. Ana pours in another $0.37$ L. How much water is in the jug now, in litres?
1. (A)
  $0.89$
2. (B)
  $8.9$
3. (C)
  $5.57$
4. (D)
  $5.47$

Answer key — Addition and subtraction of decimals

1.
10.15decimal-add-sub-01
$6.25 + 3.90 = \mathbf{10.15}$ . Estimate: $6 + 4 = 10$ .
2.
3.75decimal-add-sub-02
Spent: $13.45 + 2.80 = 16.25$ . Left: $20.00 - 16.25 = \mathbf{3.75}$ dollars. Mental check: $16.25 + 3.75 = 20$ .
3.
(C)
$5.57$
decimal-add-sub-03
$5.20 + 0.37 = \mathbf{5.57}$ L. ( $0.89$ and $8.9$ come from lining up the last digits as if adding $52 + 37$ ; $5.47$ is a tenths slip.)