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In this worksheet you have to add or subtract 100, 10 or 1 to or from a number.

 

When we add or subtract 100, it is the hundreds digit that we change.

When we add or subtract 10, it is the tens digit that we change.

When we add or subtract 1, it is the units digit that we change.

 

Remember that other digits may have to change too.

 

Example 1

What number is 100 less than 750?

 

Answer

Reduce 7 hundred by 1 hundred to get 6 hundred...

 

750 becomes 650

 

 

Example 2

What number is 10 more than 539?

 

Answer

Increase 3 tens by 1 ten to get 4 tens...

 

539 becomes 549

 

 

Example 3

What number is 1 less than 539?

 

Answer

Reduce 9 units by 1 unit to get 8 units...

 

539 becomes 538

 

 

Example 4

What number is 10 less than 405?

 

Answer

Here we have to be careful, because we can't reduce the tens digit by 1. 

So include the hundreds digit.

Think of it as reducing 40 tens by 1 ten to get 39 tens.

 

405 becomes 395

10 questions