Multiplying Decimals

Multiplying Decimals

Today I am learning that place value is used to determine decimal location.

Hoy estoy aprendiendo que el valor de la plaza se utiliza para determinar la unicación decimal.

Take Notes

Get a note catcher from the front. Look through the next few slides. Fill in the note catcher as you learn.

Obtenga un receptor de notas desde el frente. Mire las siguientes diapositivas. Complete el receptor de notas a medida que aprende.

To be successful I need to...

Para ser exitoso, necesito hacerlo...

• Take notes about estimation - Tome notas sobre la estimación.

• Take notes about strategies - Tome notas sobre estrategias.

• Answer all questions - Responde a toda preguntas.

Review Multiplication - Remember!

• Repeated Addition - Suma repetidamente

• Picture or visual

• Multiplication means groups - La multiplicación significa grupos.

​

.21

.21

+ .21

.63​

​Notes

​Repeated Addition

Strategy 1

• Think of the numbers as words - Piense en los números como palabras

• 2 x 3 hundredths = 6 hundredths

• 3 tenths x 4 tenths = 12 hundredths​

• What would you call this strategy? - ¿Cómo llamarías a esta estrategia?

Tenths​

Tenths​

Hundredths

​Notes

​ Think of place value words!

.3 x .4 = ?

3 tenths x 4 tenths = ​12 hundredths

.3 x .4 = .12​

​

Multiple Choice

Using $$.4\ \times.03\ =\ .012$$  Choose which of these answers correctly uses place value vocabulary.

• 4 tenths times 3 tenths equals 12 tenths

• 4 tenths times 3 hundredths equals 12 hundredths

• 4 times 3 equals 12

• 4 tenths times 3 hundredths equals 12 thousandths

Strategy 2

• Use a visual to show the multiplication. Usa una visual para representar la multiplicación.

  ​

• What would you call this strategy? - ¿Cómo llamarias a esta estrategia?

​Notes

​

​.2

​.1

​.2 x .1 = .02

Multiple Select

Which two images correctly show the equation 1.2 x .6?

Strategy 3

• Convert numbers into fractions - Convertir los números a fracciones.

• Multiply across - Múltiples fracciones.

• Convert to decimal - Convertir de nuevo a los decimales.

​Notes

​Turn the decimal into a fraction

• .8 to 8/10

• .2 to 2/10​

Multiply across the fractions

• ​8/10 x 2/10 = 16/100

Turn the fraction back into a decimal​

• 16/100 to .16​

Multiple Choice

Which of the following correctly converts 1.2 x .03 to fractions?

• $$\frac{12}{100}\times\frac{3}{100}=\frac{36}{10,000}$$  

• $$\frac{12}{10}\times\frac{3}{100}=\frac{36}{1,000}$$  

• $$\frac{12}{1}\times\frac{3}{100}=\frac{36}{100}$$  

• $$\frac{12}{10}\times\frac{3}{10}=\frac{36}{100}$$  

Poll

Which of the previous strategies do you plan on using when multiplying decimals? - ¿Cuál de las estrategias anteriores planeas usar cuando multiplican decimales?

• Strategy 1 - Repeated Addition

• Strategy 2 - Words

• Strategy 3 - Picture/Visual

• Strategy 4 - Write as fractions

Multiple Choice

$$7\times5=35,\ so\ 7\times.5\ =\ ?$$  

• 35

• .35

• 3.5

• 28

Multiple Choice

$$12\times4=48,\ so\ .12\times4=?$$  

• .16 (16 hundredths)

• .48 (48 hundredths)

• 4.8 (48 tenths)

• 48 (48 wholes)
  

Multiple Choice

$$8\times4=32,\ so\ .08\times.4=?$$  

• 32 (32 wholes)

• 3.2 (32 tenths)

• .32 (32 hundredths)

• .032 (32 thousandths)

Multiple Choice

$$60\times3=180,\ so\ 60\times.3=?$$  

• 18.0

• 1.80

• .180

• .018

Open Ended

Solve.

$$9\times.04=$$  

Poll

How are you feeling about multiplying decimals?

• I am still confused.

• I think I get it.

• I'm feeling confident.