Multiplying Decimals

1. Bob had 3 packets of butter each containing 0.4 kg butter.
How much butter did Bob have altogether?

Method 1:
0.4  +  0.4  +  0.4  =  1.2 kg
Bob had 1.2 kg of butter altogether.

Method 2:
Multiply 0.4 kg by 3.
0.4  ×  3  =  ?

square metre or square meter
square metre or square meter
Bob had 1.2 kg of butter altogether.

2. Bob had 3 cartons of milk each containing 0.45 L of milk.
How much milk did Bob have altogether?

Multiply 0.45 L by 3.
0.45  ×  3  =  ?

square metre or square meter
square metre or square meter
Bob had 1.35 L of milk altogether.

3. Bob had 7 bags of flour each containing 1.85 kg flour.
How much flour did Bob have altogether?

Multiply 1.85 kg by 7.
1.85  ×  7  =  ?

square metre or square meter
Bob had 12.95 kg of flour altogether.

4. Serena bought 5 drawing books for $4.25 each.
How much did she spend on the drawing books altogether?

Cost of 1 drawing book   =   $4.25
Cost of 5 drawing books   =   $4.25  ×  5
=   $21.25

She spent $21.25 on the drawing books altogether.
square metre or square meter