Mental vs Written Methods (Ex. 2)

What's in this exercise

Answers are hidden — sign up to practise and check your work.

1. Question 1

   Multiple choice

   A student says: 'I'll use a written method for 1,000,000 − 999,999.' Is this the best choice?

2. Question 2

   Multiple choice

   Which of these should be solved with a written method?

3. Question 3

   Multiple choice

   Lena calculates 7,000,000 − 2,500,000. The best mental strategy is:

4. Question 4

   Sequence

   Which method? Written=W, Mental=M. 999 + 1 = ___, 4,567,890 + 3,210,456 = W, 100,000 − 100,000 = ___.

5. Question 5

   True or false

   When numbers are near multiples of a large power of 10, mental methods can be very efficient.

More exercises in this module

• Mental vs Written Methods (Ex. 3)

• Large Addition Across Millions (Ex. 5)

• Large Subtraction from Millions (Ex. 6)

• Mixed Operations with Millions (Ex. 7)

• Six-Digit Addition (Ex. 1)

• Adding & Subtracting Large Integers (Ex. 3)