Adding Tens

Front

What is the result of adding 10 to a two-digit number?

Back

To add 10 to a two-digit number, simply increase the tens place by 1 while keeping the units place the same.

Front

How do you add 20 to a number?

Back

To add 20 to a number, increase the tens place by 2 while keeping the units place the same.

Front

What is the sum of 135 and 10?

Back

The sum of 135 and 10 is 145.

Front

What is the sum of 199 and 10?

Back

The sum of 199 and 10 is 209.

Front

What is the sum of 123 and 20?

Back

The sum of 123 and 20 is 143.

Front

What is the sum of 100 and 10?

Back

The sum of 100 and 10 is 110.

Front

What is the sum of 191 and 20?

Back

The sum of 191 and 20 is 211.

Front

What is the principle behind adding tens to a number?

Back

The principle is to increase the value of the number by the amount represented by the tens added.

Front

How does adding 10 affect the value of a number?

Back

Adding 10 increases the number by one decade, shifting it to the next higher ten.

Front

What is a quick method to add 10 or 20 to a number?

Back

A quick method is to mentally adjust the tens place while keeping the units place unchanged.