Mind Castle — Lesson 102: Picture the abacus in your head

What your child does, card by card

Picture the abacus in your head. See the beads with your eyes closed. PlayType opens the lesson: “The best abacus is the one in your head.”

See it, then see it again: the beads show a number. Close your eyes: can you still see it? The abacus makes 7, 23 and 58, then clears. Above, “See 7”, “See 23” and “See 58” take turns to glow. Its words: “Tap a bead to try it.”

In your head: the beads flash 7, 23, 58 and 106, one at a time, for 1.5 seconds each and hide; your child picks the number from 7, 23, 58, 85 and 106, then sees the beads again.

Move them in the air: your fingers move. The beads are in your head. 4 appears on the beads, then the rod clears again. Here the hands lead: they show 4 and 9, and a moment later the beads copy each one. On the card, “See 4”, “+ 5: the top bead” and “See 9” light up one by one. Then the card invites a touch: “4 + 5: four fingers, then the thumb.”

In your head: the abacus is covered and your child works out 4 + 5, 7 - 3 and 20 + 30, picking each answer from 4, 9 and 50.

You're ready! The best abacus is the one in your head.

What this lesson trains

About five minutes and 7 answers. Altogether the child makes 0 bead moves (0 with the top bead, 0 with bottom beads). The biggest number is 0, all on the ones rod; the 2 rods to its left stay clear and are named on a touch. Then 4 quick looks in your head.

Fingers and hands

In the lower window two drawn hands work as a finger abacus and always match the beads: a finger up is a bottom bead (1), the thumb out is the top bead (5), a closed hand is zero. In this lesson the hands show zero and 4, 7, 9, 23 and 58.

On “Move them in the air” 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.

What PlayBuddy and PlayType say

PlayType: “The best abacus is the one in your head.”

PlayBuddy: “Close your eyes and see the beads. Now move them with your fingers, in the air.”

Stars

With no slips across the 7 answers your child earns three stars; 1 or fewer, two. A number counts as a slip only when it stays wrong for a moment and is not on the way to the answer, so a child who moves beads one at a time is never marked down. After two slips on one task the green ring comes back.

About Mind Castle

Mind Castle is Level 9 of nine (grade 4 and up): faster flashes, more numbers, listening sums. In your head: all in your head.