Math Learning Steps

Meaning for the numbers 10 to 20

At first, the numbers above 9 can be thought of as just the next numbers that come along. There is nothing wrong with that, and that viewpoint will work just fine for a long time. Eventually, with numbers all the way up to 100 coming on the horizon, it will be time to Introduce your child to the role of 10 in the numbers from 10 to 20.

Adding and subtracting 10

Start this introduction by helping your child learn how to add 10 to single-digit numbers and subtract 10 from double-digit numbers from 10 to 20.

Practice with physical quantities

Find something you have a lot of – perhaps pebbles, sticks, or toothpicks. Let’s use 3 and 13 as an example. If you place 13 things on a flat surface, you can separate them into one group of 10 and one group of 3. This demonstrates both that 3 + 10 is 13, and also that 13 – 10 is 3.

Numerals

If your child is ready to use numerals, write down 13 = 10 + 3 and 13 – 10 = 3 as you do the demonstration just described. When we write a two-digit number, such as 13, the place on the left is the tens place and the place on the right is the ones place. Then tens place tells how many tens the number has, and the ones place how many ones it has. For 13, it is made up of 1 ten and 3 ones, so 13 = 10 + 3. As another example, 20 is made up of 2 tens and 0 ones.

It takes time

Breaking up a number into tens and ones, particularly symbolically with written numbers, is a big conceptual step and you should expect this to take many demonstrations, many explanations, and lots of time. As with so many of these foundational elements, your child will absorb it eventually and there is no hurry.