Lesson 22: Two-digit abacus practice for kids
Level 2, Easy Street. Add and take away tens and ones. Then beat your best time!
What your child does, card by card
Two-rod practice. Practice day! PlayBuddy opens the lesson: “Practice time. Let's get quicker and better.”
First a reminder (“15 + 52 = 67”): the beads build 15, 65 and 67, ring by ring, while your child watches. Tens first, then ones.
Try it: your child works out 13 + 21 and 78 - 27, with a green ring on the next bead to move.
Six sums, fast: a mission of 6 tasks with a clock against your child’s own best time. Your child must work out 21 + 55, 98 - 36, 50 + 37, 96 - 51, 12 + 82 and 89 - 24.
Copy me: the hand in the lower window shows 66, 42 and 95, one at a time, and your child makes the same number on the beads.
Then the beads hide and the sums 11 + 22, 57 - 5 and 90 - 20 are done in the head, the answer shown on the fingers.
You're ready! Tens and ones, both ways, and fast!
What this lesson trains
14 answers, roughly five minutes: 29 moves of the beads, 11 of them with the top bead and 18 with bottom beads. Up to 98, read and set from the left. Then 3 quick looks in your head.
It starts with doing: work out 13 + 21 and 78 - 27.
Fingers and hands
Below the abacus the drawn hands show zero and 12, 13, 21, 34, 42, 45, 50, 51, 62, 65, 66, 76, 78, 87, 89, 94, 95, 96 and 98 here, finger for bead: the left hand counts the tens, the right hand the ones.
In Copy me the hand leads with 66, 42 and 95 and your child turns each into beads.
What PlayBuddy and PlayType say
PlayBuddy: “Practice time. Let's get quicker and better.”
PlayBuddy: “Click Let's Begin, or press Enter!”
PlayType: “First the tens, and then the ones.”
PlayType: “Now let's try a harder one.”
Stars
14 answers: 1 slip still gives three stars; up to 3, two stars.