Hen Crossing: An Addition and Subtraction Game Within 20
The hungry hen wants her grain. Answer the sums to help her cross the road, one lane at a time.
Getting the game ready...
For grown-ups
A hungry hen wants the grain on the far side of the road, and your child gets her there one lane at a time. Each lane is an addition or a subtraction question, within 10 for the first level and within 20 for the second. A right answer moves the hen forward one lane. A wrong answer brings up a number line so your child can see the jump and try again. It suits children in Grades 1 and 2, and keen Kindergarten children can enjoy the within-10 level with a grown-up beside them.
Why facts within 20 matter so much
Nearly every bigger calculation children will do later rests on these small facts. When a Grade 3 child adds 48 + 7, they are really using 8 + 7 = 15. When a Grade 4 child subtracts 63 - 9, they are using 13 - 9 = 4. If those little facts take a long count each time, the bigger work becomes slow and full of slips, and children start to feel they are "bad at math" when the real issue is just that the foundation is still being built.
So this game is worth the time. It is not about racing. It is about making these facts familiar enough that, eventually, children do not have to work them out at all.
The strategies children use
Children rarely go straight from counting to instant recall. They pass through strategies, and you can hear which one they are using if you ask "How did you know?"
| Strategy | What it sounds like for 8 + 5 | When it shows up |
|---|---|---|
| Counting all | "One, two, three... thirteen" (counts both groups) | Early Kindergarten and Grade 1 |
| Counting on | "Eight... nine, ten, eleven, twelve, thirteen" | Grade 1 |
| Making ten | "Eight and two is ten, and three more is thirteen" | Late Grade 1, Grade 2 |
| Using doubles | "Five and five is ten, plus three is thirteen" | Grade 1 and 2 |
| Just knowing | "Thirteen" (no pause) | Grows over Grade 2 |
Every one of these is a real piece of math. Counting on is a big step up from counting all. Making ten is the strategy I most want children to have, because it works for every bridging fact and it carries over to subtraction: 13 - 5 is "take three to get to ten, then two more, eight."
The hints, explained
When your child gets a lane wrong, the game shows a number line. A number line is just the counting numbers in a row, with jumps drawn as arcs. For 8 + 5, the hint shows a jump of 2 to land on 10, then a jump of 3 to land on 13. This is the making-ten strategy, drawn as a picture.
The ten frame is the other useful picture, and you can draw one at home: a box of two rows with five squares in each row. Fill eight squares with dots and it is obvious that two more fill the frame. Children who see "eight is two less than ten" without counting are well on their way.
Playing together
Sit beside your child and let them read each question aloud. After a right answer, ask now and then (not every time), "How did you get that?" You are not checking. You are curious, and you will learn which strategy they reach for.
When the hint comes up, let your child trace the jumps with a finger before trying again. If they guess a second time without looking, gently point back at the picture. Five to ten minutes is a good session. Getting the hen across two or three times is a nice place to stop.
A sidewalk version with chalk
On a dry day, draw a road on the sidewalk with chalk: six lanes, each about a big step wide, with a pile of "grain" (a few pebbles or a small bag of dried beans) at the end. Your child stands at the start holding a small toy animal. You call out a question, and a right answer lets the toy (and the child) step forward a lane.
For a kitchen table version, draw the same lanes across a sheet of paper and use any small toy. A shuffled deck of cards (aces as 1, face cards removed) makes the questions: flip two cards and add them, or take the smaller from the bigger. That gives you sums to 20 and differences within 10 without having to think up questions yourself.
Signs a child is still counting every time
- Lips moving, or a nod for each number.
- Fingers held up for both numbers, even for something like 9 + 1.
- The same pause for 2 + 2 as for 7 + 6.
- Subtraction done by counting backward one at a time, with frequent off-by-one slips (14 - 5 coming out as 10 or 8).
None of these is a worry in Grade 1. If they are still the main approach late in Grade 2, it helps to work on a few facts at a time rather than all of them. Start with the pairs that make ten (1 and 9, 2 and 8, 3 and 7, 4 and 6, 5 and 5), then the doubles, then the "one more than a double" facts. Count on fingers together if they want to, then ask "Can we do it a faster way?" and show the making-ten move.
What to watch for
The off-by-one slip in subtraction is the most common error I see. A child counting back for 12 - 4 often says "twelve, eleven, ten, nine" and lands on nine, because they counted the starting number. On the number line, show that each jump is a space between numbers, not a number itself.
Children who move quickly through this game can take the same facts into a different setting with the Space Bricks mission later on, and more at-home ideas are in Math at Home, with the rest of the collection on the games page. For now, pull five beans from the jar, hide two in your hand, and ask how many are missing.
