The make 10 strategy is a way to add by filling up a ten first. For 8 + 5, take 2 from the 5 to turn 8 into 10, then add the 3 left over: 10 + 3 = 13. It depends on knowing the pairs that make 10, and it turns harder facts into easy ones.
Ten is the easiest number to add to. Once a child knows that 10 + 3 is thirteen, any sum that crosses 10 can be split into "fill the ten, then add the rest." That's the whole idea.
The Common Core first grade standards list "making ten" as one strategy for adding within 20, with this example: 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14. In England, the National Centre for Excellence in the Teaching of Mathematics (NCETM) calls it bridging 10, and its teaching materials describe adding two numbers that cross the tens boundary "by using a 'make ten' strategy." Make 10, making ten and bridging through 10 all mean the same move.
The make 10 strategy rests on two smaller skills. The kindergarten standards cover both:
Knowing the partner that makes 10. For any number from 1 to 9, children find the number that makes 10 with it. The pairs are 1 + 9, 2 + 8, 3 + 7, 4 + 6 and 5 + 5, plus the same pairs flipped.
Splitting small numbers. Children break numbers up to 10 into pairs in more than one way, such as 5 = 2 + 3 and 5 = 4 + 1.
If your child still counts on fingers to find the partner of 7, practice the pairs before teaching the strategy. Our guide to number bonds to 10 has games for this.
Build it. Draw a ten frame, a grid of 2 rows of 5 boxes. Put 8 counters in it and 5 counters next to it. Ask, "How many more fill the frame?" Move 2 in. Now there's a full ten and 3 left: 13.
Say it. "8 needs 2 to make 10. I split 5 into 2 and 3. Ten and 3 is 13." Saying the steps out loud helps them stick.
Draw it. Sketch the 5 splitting into 2 and 3 underneath the problem. Then write 8 + 5 = 8 + 2 + 3 = 10 + 3 = 13.
Hop it. On a number line, jump from 8 to 10, then 3 more to 13.
Think it. Once the pictures feel easy, try a few in your head, and ask your child to explain each step.
9 + 4: 9 needs 1. Split 4 into 1 and 3. 10 + 3 = 13.
8 + 6: 8 needs 2. Split 6 into 2 and 4. 10 + 4 = 14.
7 + 5: 7 needs 3. Split 5 into 3 and 2. 10 + 2 = 12.
6 + 8: start with the bigger number. 8 needs 2. Split 6 into 2 and 4. 10 + 4 = 14. NCETM's materials stress that the order you add in doesn't change the total, so choose the easier order.
9 + 9: 9 needs 1. Split 9 into 1 and 8. 10 + 8 = 18.
The same move works for the next ten. The first grade standards include adding a two-digit number and a one-digit number, and note that sometimes you need to make a new ten.
28 + 5: 28 needs 2 to reach 30. Split 5 into 2 and 3. 30 + 3 = 33.
47 + 6: 47 needs 3 to reach 50. Split 6 into 3 and 3. 50 + 3 = 53.
65 + 7: 65 needs 5 to reach 70. Split 7 into 5 and 2. 70 + 2 = 72.
The first grade standards also describe "decomposing a number leading to a ten," with the example 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9. NCETM describes two ways to subtract across 10:
Subtract through ten: for 13 - 4, take away 3 to land on 10, then 1 more to get 9.
Subtract from ten: split 13 into 10 and 3. Take 4 from the 10 to get 6, then add back the 3 to get 9.
When adding three numbers, NCETM suggests choosing the most efficient order, including looking for two numbers that make ten.
7 + 6 + 3: add 7 + 3 first to make 10, then add 6 to get 16.
4 + 8 + 6: 4 + 6 is 10, and 10 + 8 is 18.
Ten frame flash. Show a ten frame with some counters for two seconds. Your child says how many more make 10.
Finger flash. Hold up 7 fingers. Your child holds up the 3 that are "missing."
Make 10 Go Fish. Use cards ace to 9. Instead of asking for a match, ask for the card that makes 10 with one in your hand.
Pairs to 10. Lay cards ace to 9 face down. Flip two at a time and keep them if they make 10.
Bridge the gap. Draw a card from 6 to 9 and roll a die. Add them out loud using the make 10 steps.
Egg carton ten frame. Cut an egg carton down to 10 cups and fill it with pasta or buttons.
Floor number line. Tape 0 to 20 on the floor. Hop to 10 first, then hop the rest.
Slow on the partners of 10. Go back to number bonds and practice them with games.
Unsure how to split the second number. Practice splitting small numbers, like "6 is 2 and 4."
Losing the leftover. Write it down, or keep it in a separate pile of counters.
Using it everywhere. For 8 + 1, counting on is faster. For 5 + 5, a known double is quicker. Make 10 is a tool, not a rule.
To see where this fits in the bigger picture, read our guides on how to teach addition and number bonds to 20.
Under the Common Core, kindergartners learn to find the number that makes 10 with any number from 1 to 9. In first grade, they use making ten as a strategy for adding and subtracting within 20.
Yes. Bridging through 10 is the term common in England, and make 10 or making ten is common in the US. Both mean filling a ten first, then adding the rest.
Number bonds are the pairs that make a number, such as 3 + 7 = 10. Make 10 is a strategy that uses those pairs to add or subtract across 10.
Yes. Fill up to the next ten instead. For 28 + 5, add 2 to reach 30, then 3 more to get 33.
Number Beasts: Bond Lab is a free puzzle game built around make 10. You launch a number at a beast, and when the two add up to exactly 10 the beast pops; overshooting still pops it, and the leftover number keeps flying to the next beast, a lot like the 3 left over in 8 + 5. It has no ads, accounts, tracking or in-app purchases, and the whole game works offline.
Get Number Beasts free on the App Store
Common Core State Standards: Kindergarten, Operations and Algebraic Thinking
Common Core State Standards: Grade 1, Operations and Algebraic Thinking, standard 1.OA.C.6
Common Core State Standards: Grade 1, Number and Operations in Base Ten
Addition and subtraction: bridging 10 (NCETM primary mastery materials)