Big Friends Bridge — Lesson 54a: Which way to take away?

What your child does, card by card

Which way to take away? Beads, small friend, or big friend? PlayBuddy opens the lesson: “First try the beads. Then the small friend. Then the big friend.”

9 − 4 = 5: four bottom beads are on the bar. Take them! The beads show 9 and go back to zero. Here the hands lead: they show 9 and 5, and a moment later the beads copy each one. The labels “Start at 9” and “4 beads there: take = 5” light up as each idea comes. “Enough beads? Just take them.” Any bead or finger may be tapped afterwards.

7 − 4 = 3: only 2 bottom beads. But the top bead is there. 7 appears on the beads, then the rod clears again. Here the hands lead: they show 7, 2 and 3, and a moment later the beads copy each one. On the card, “Start at 7”, “−5” and “1 back = 3” light up one by one. Then the card invites a touch: “Take 5, give 1 back.”

12 − 4 = 8: only 2 ones. No top bead. Not enough! The abacus makes 12, then clears. Here the hands lead: they show 12, 2 and 8, and a moment later the beads copy each one. Each label lights in turn: “Start at 12”, “−10” and “6 back = 8”. After the show, the child can touch: “Take a ten, give 6 back.”

First a reminder (“19 − 4 − 4 − 4”): the beads build 19, 15, 10, 11, 1 and 7, ring by ring, while your child watches. Take. Small friend. Big friend.

Try it: your child works out 18 - 3, 15 - 3 and 12 - 3, with a green ring on the next bead to move, changing the beads from one number to the next.

Which way?: a mission of 8 tasks with a count of right answers in a row, with the best kept. Your child must work out 9 - 4, 7 - 4, 12 - 4, 5 - 2, 16 - 4, 11 - 3, 8 - 3 and 13 - 4.

Copy me: the beads show 5, 3, 8 and 12 and your child answers by tapping the drawn fingers, the hands window glowing.

In your head: the abacus is covered and your child works out 9 - 4, 7 - 4 and 12 - 4, showing each answer on the drawn fingers.

You're ready! Beads there? Take them. Top bead there? Small friend. Neither? Big friend.

What this lesson trains

About five minutes and 18 answers. Altogether the child makes 23 bead moves (8 with the top bead, 15 with bottom beads). Numbers reach 18, so the tens rod and the ones rod work. Then 3 quick looks in your head. 8 of the 11 sums need a friend (“−3 = −5 +2”, “−3 = −10 +7”, “−4 = −5 +1”, “−4 = −10 +6” and “−2 = −5 +3”); the others use free beads.

The first thing your child does: work out 18 - 3, 15 - 3 and 12 - 3.

Fingers and hands

Below the abacus the drawn hands show zero and 2, 3, 5, 7, 8, 9, 11, 12, 13, 15, 16, 18 and 19 here, finger for bead: the left hand counts the tens, the right hand the ones.

−3 on the fingers: the thumb closes and 2 fingers open (−5 +2). −4 on the fingers: the thumb closes and one finger opens (−5 +1). −2 on the fingers: the thumb closes and 3 fingers open (−5 +3).

−3 on the fingers: the left hand closes one finger for the ten and the right hand shows 7 more (−10 +7). −4 on the fingers: the left hand closes one finger for the ten and the right hand shows 6 more (−10 +6).

On “9 − 4 = 5” 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.

In Copy me the beads lead with 5, 3, 8 and 12, and your child answers on the fingers: the reverse of making a number on the beads.

What PlayBuddy and PlayType say

PlayBuddy: “First try the beads. Then the small friend. Then the big friend.”

PlayType: “To take away, move beads off the bar.”

PlayBuddy: “Taking five is one too many. So one bead comes back!”

PlayBuddy: “One ten off, big friend on.”

PlayBuddy: “Don't clear. The beads keep the answer.”

Stars

With 1 or fewer slips across the 18 answers your child earns three stars; 4 or fewer, two.