Mental Math: Estimate Quotients

Mental Math: Estimate Quotients

By Sela Pajarillo

When choosing an estimation technique, choose one that uses numbers that are easy to compute mentally.

​

​Use compatible numbers - numbers that are easy to compute

​

Open Ended

​120 and 6 are compatible numbers --- 120÷6=20

If using rounding: 132÷6 --- 100÷6, which is not easy to divide mentally by 6.​

Multiple Choice

Max wants to make 9 rubber balls out from 700 rubber bands.

• More balls

• Fewer balls

​Max wants to make 9 rubber balls out from 700 rubber bands.

​Fewer balls; He would need atleast 720 rubber bands if he wants to make 9 balls with 80 rubber bands each.

Multiple Choice

• YES

• NO

​Yes; 700 is close to 720, and 720 ÷ 8 = 90 rubber bands per ball.

Draw

Estimate each equations. Use compatible numbers.

48 ÷ 5

Draw

Estimate each equations. Use compatible numbers.

235 ÷ 8

Draw

Estimate each equations. Use compatible numbers.

547 ÷ 6

Draw

Estimate each equations. Use compatible numbers.

192 ÷ 5

Draw

Estimate each equations. Use compatible numbers.

662 ÷ 8

Draw

Estimate each equations. Use compatible numbers.

362 ÷ 3

Draw

Estimate each equations. Use compatible numbers.

41 ÷ 2

Draw

Estimate each equations. Use compatible numbers.

211 ÷ 4