Transcript Multiplying Numbers with decimals

Multiplying Numbers with
decimals
2.3
x 4.2

Decimals DO NOT have to be lined up
when multiplying
2.3
x 4.2
Imagine that the number does NOT have
decimals
 Solve
23
X 42

23
x 42
46
+920
966
(Don’t forget to add place holder)

Next, count the number of places AFTER
each decimal
2.3 (One place after decimal)
x 4.2 (One place after decimal)

In the answer, count right to left the
number of “spaces” that match the
number of places after the decimals in the
previous step. PLACE the DECIMAL
THERE.
Answer: 966

Move 2 decimal places
9.66 (count right to left)
Final Problem
2.3
x 4.2
46
+920
9.66
(Don’t forget to add place holder)
You Try
34.5
x 0.12
690
+ 3450 (Don’t forget place holder)
4140 (Don’t forget to count number of decimals)
Final answer 4.140
(decimal moved 3 places)
How many places will you move the
decimal “in”?
1)
234.123
x 3.4
2) 98.33
x 1.3
3) 674
x 43.89