Mental Subtraction

Mental Subtraction

Mental Skills (page 70)

Mental Subtraction

When we subtract numbers mentally, we are trying to find a quick way of subtracting the numbers in our heads. Let us take a look at some examples.

Multiple Choice

Min wants to find the difference between 185 and 29.

• 154

• 155

• 156

• 157

Fill in the Blanks

Subtract 198 from 367 mentally.

Multiple Choice

What is 569 - 53?

• 515

• 516

• 517

• 518

Fill in the Blanks

Subtract 304 from 686 mentally.

Fill in the Blanks

Subtract 4 from 802 mentally.

Find Doubles and Halves Mentally

Multiplying and Dividing Mentally (page 72)

Fill in the Blanks

Rita has 100 stamps in her stamp album. Min has double the number of stamps. How many stamps does Min have?

Open Ended

How do we find double 120 mentally?

Fill in the Blanks

Tom had 80 toy cars. He gave half of them to Ari. How many toy cars did Tom give to Ari?

Fill in the Blanks

Can you find half of 800 mentally?

Open Ended

How can we find half of 50 mentally?

Fill in the Blanks

Find half of 240 mentally.

page 74