6.2 Estimation

6.2 Estimation

When estimating...

• Use rounding

• Use compatible numbers

Rounding

To round, I underline the digit I am rounding to. Then, I look to the right. If the number is 5 or more, I round up. If the number is four or less, I round down.

Multiple Choice

Round 473.89 to the nearest whole number.

• 470

• 473

• 474

• 473.9

Multiple Choice

Round 53.1 to the nearest whole number.

• 50

• 53

• 54

• 53.1

Compatible Numbers

Find numbers that are easy to calculate in your head.

Multiple Choice

Which expression uses compatible numbers?

• $13\div4$

• $178\div5$

• $64\div8$

Multiple Choice

What expression uses compatible numbers?

• $100\div10$

• $95\div25$

• $12,655\div12$

Estimating

Choose the answer that will have the closest estimate.

Multiple Choice

What is the best estimate?

 $52.3\div11.4$  

•  $52\div10$  

•  $55\div5$  

Multiple Choice

What is the best estimate?

 $25.1\div8=$  

•  $25\div5$  

•  $24\div8$  

Multiple Choice

What is the best estimate?

 $9.6\div0.91=$  

•  $10\div1$  

•  $9\div0$