Knowing how to add a 1-digit number to a 2-digit number mentally is essential for mastering the times tables. Use this scripted lesson and fun game to teach your child this important mental addition skill and get her ready to memorize the multiplication facts.
Stepping-stone facts are one of the fastest and easiest ways for children to master the multiplication facts. But first, children have to be skilled at adding a 1-digit number to a 2-digit number mentally.
To teach your child this vital skill, begin with the scripted lesson below. Then, encourage your child to use the same strategy as you play this advanced version of Race to 100. Make sure to keep your ten-frames handy!
(Excerpted from Multiplication Facts That Stick. Parent’s words are in quotation marks and child’s sample answers are in italics.)
- 16 small counters
- Paper and pencil
- Ten-frames, cut apart on the dotted lines (See the link at the bottom of the page to download your own printable ten-frames.)
Write 29 + 3 = on a piece of paper. “We’ll use ten-frames and counters to show this problem. Ten-frames are just grids with 10 dots in them.”
“Instead of using 29 counters to show the problem, we’re going to save time and use 2 ten-frames that are already filled in. Each dot in a ten-frame stands for a counter.” Place two full ten-frames and one empty ten-frame on the table. Fill the empty ten-frame with 9 counters from left to right.
“There are 2 tens, plus 9 more counters, for a total of 29. Now, we need to add 3.” Place 3 counters of another color next to the ten-frames.
“Let’s fill in the empty spot in the ten-frame to make it easier to see the answer to the problem.” Move 1 loose counter to the empty spot in the ten-frame.
“How many tens are filled in now?” 3.
“How many loose counters are there?” 2.
“So, what’s 29 + 3?” 32. (If your child’s not sure, ask, “What do the 3 tens equal?” 30. “So, what’s 30 and 2 more?” 32.)
Repeat this process with the following problems. Each time, have her complete the empty boxes in the partially-full ten-frame to make it easier to find the answer.
Race to 100 Directions
- 5s, 6s, 7s, 8s, 9s, and 10s a deck of cards
- Paper and pencil
- 20 small counters
- Ten-frames, cut apart on the dotted lines (See the link at the bottom of the page for your own printable ten-frames.)
Object of the Game
Be the first player to reach 100.
Shuffle the cards and place them in a face-down pile. On your turn, flip over a card. Add the number on the card to your score. The first player whose score is 100 or higher wins.
Encourage your child to use the ten-frames and counters as needed to figure out his new total. As he becomes more confident at mental addition, see if he can solve the problems simply by visualizing the ten-frames rather than modeling the problem with physical counters.