Estimating Products of Multi-Digit Numbers

Why do we estimate products instead of calculating the exact numbers?

• To avoid using a calculator

• To make the numbers smaller

• To get a more accurate result

• To save time in multiplying

How many cakes can Cherry bake in 12 months if she bakes 102 cakes per month?

• 1224

• 1200

• 1100

• 1000

What is the estimated product of 102 cakes per month for 12 months?

• 1224

• 1100

• 1000

• 1200

What is the first step in rounding off numbers?

• Copy all the zeros

• Change all digits to zero

• Identify the rounding digit

• Multiply the digits

If the next digit after the rounding digit is 5 or more, what should you do?

• Change it to zero

• Round up

• Keep the digit the same

• Round down

What is 84,622 rounded to the nearest ten thousand?

• 84,000

• 80,000

• 85,000

• 90,000

What is the first step in estimating the product of two numbers?

• Multiply the non-zero digits

• Copy all the zeros

• Round off the multiplicand and multiplier

• Add the numbers

What makes the multiplication step easier in estimating products?

• Using a calculator

• Adding the numbers first

• Copying all the zeros

• Rounding down the digits

What is the estimated product of 102 and 12 after rounding?

• 1300

• 1100

• 1000

• 1200

What is the final step in estimating the product of two numbers?

• Multiply the non-zero digits

• Copy all the zeros

• Round off the digits

• Add the numbers