Lesson 14a: Adding 6, 7, 8 and 9 on an abacus
Level 2, Easy Street. Top bead down, bottom beads up.
What your child does, card by card
Adding 6, 7, 8 and 9. Plus 5, and some more. PlayType opens the lesson: “What comes after five? Five and one more.”
1 + 6 = 7: 6 is 5 and 1. Add 5, then add 1. The beads show 1 and go back to zero. Here the hands lead: they show 1, 6 and 7, and a moment later the beads copy each one. Above, “+5: the top bead”, “+1: one bead” and “= 7” take turns to glow. Its words: “Read the beads: that is the answer.”
2 + 7 = 9: 7 is 5 and 2. Add 5, then add 2. 2 appears on the beads, then the rod clears again. The labels “+ 5 = 7” and “+ 2 = 9” light up as each idea comes. “8 is 5 and 3. 9 is 5 and 4.” Any bead or finger may be tapped afterwards.
One pinch does both, on a real abacus. Pointer brings the top bead down. Thumb pushes up. Below, one drawn right hand lights the thumb and the pointer finger as the beads go. Next it is your child’s turn to work out 1 + 6 and 2 + 7; a green ring marks each bead, and the finger’s name sits by the hand. One pinch adds 6, 7, 8 or 9.
In Try it a green ring marks the next bead while your child works out 1 + 6, 2 + 7, 0 + 6, 1 + 8 and 0 + 9.
The tiny practice drops the ring: work out 3 + 6, 0 + 7, 2 + 6, 0 + 8 and 1 + 7, each round starting from its own number.
Copy me: the hand in the lower window shows 7, 9 and 8, one at a time, and your child makes the same number on the beads.
Then the beads hide and the sums 1 + 6, 2 + 7 and 0 + 8 are done in the head, the answer shown on the fingers.
You're ready! Plus 6, 7, 8 and 9: the top bead and some more.
What this lesson trains
18 answers in about five minutes. The tasks take 30 bead moves in all: 15 with a top bead and 15 with bottom beads. Nothing goes past 9. Then 3 quick looks in your head.
The first thing your child does: work out 1 + 6 and 2 + 7.
Fingers and hands
Below the abacus the drawn hands show zero and 1, 2, 3, 6, 7, 8 and 9 here, finger for bead.
On “1 + 6 = 7” the hands move first and the beads follow, so your child sees that a finger and a bead move together: open a finger and a bead goes to the bar, close it and the bead goes back.
Copy me turns it round: 7, 9 and 8 appear on the hand first.
On “One pinch does both”, the thumb and the pointer finger pinch together, so the top bead and the bottom beads reach the bar in one move.
What PlayBuddy and PlayType say
PlayType: “What comes after five? Five and one more.”
PlayType: “Six is five and one. So add five, then add one.”
PlayBuddy: “To add, push beads to the bar.”
Stars
With 1 or fewer slips across the 18 answers your child earns three stars; 4 or fewer, two.