Small Friends Pond — Lesson 33: Small friends: minus 3
Small friends: minus 2 and minus 1 →Lesson 33: Small friend minus 3 on an abacus
Level 3, Small Friends Pond. Minus 3: take 5, give 2 back.
What your child does, card by card
Small friends: minus 3. 3 and 2 make 5. PlayType opens the lesson: “Same trick, new friend.”
6 − 4 = 2: take 5. That is 1 too many. Give 1 back. The beads show 6 and go back to zero. Here the hands lead: they show 6, 1 and 2, and a moment later the beads copy each one. Each label lights in turn: “−5” and “1 back = 2”. After the show, the child can touch: “The trick of lesson 32.”
6 − 3: only 1 bottom bead is on the bar. 6 appears on the beads, then the rod clears again. “Start at 6” and “− 3? Only 1 there” glow on the card in step with the beads. The card ends on a touch: “3 will not come off. So take 5!”
Minus 3: take 5, give 2 back: 5 is 3 and 2. Taking 5 is 2 too many. The beads act out the friend rule while “−5: the top bead”, “+2: the friend” and “−3 = −5 +2” light up; then your child must work out 6 - 3 and 5 - 3, a green ring on each bead in the friend's order.
In Try it a green ring marks the next bead while your child works out 7 - 3, 5 - 3 and 6 - 3.
The tiny practice drops the ring: work out 7 - 3, 4 - 3, 5 - 3, 8 - 3 and 6 - 3, each round starting from its own number.
In Copy me the drawn hand holds up 3, 4 and 2 in turn, and your child copies each one in beads.
In your head: the abacus is covered and your child works out 5 - 3, 7 - 3 and 6 - 3, showing each answer on the drawn fingers.
You're ready! Not enough beads to take 3? Take 5, give 2 back.
What this lesson trains
16 answers, roughly five minutes: 21 moves of the beads, 8 of them with the top bead and 13 with bottom beads. Nothing goes past 8. Then 3 quick looks in your head. Small friends do 8 of the 10 sums, by −3 = −5 +2.
It starts with doing: work out 7 - 3, 5 - 3 and 6 - 3.
Fingers and hands
Below the abacus the drawn hands show zero and 1, 2, 3, 4, 5, 6, 7 and 8 here, finger for bead.
−3 on the fingers: the thumb closes and 2 fingers open (−5 +2).
On “6 − 4 = 2” 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: 3, 4 and 2 appear on the hand first.
What PlayBuddy and PlayType say
PlayBuddy: “Taking five is one too many. So one bead comes back!”
PlayType: “Not enough beads. Ask the small friend.”
Stars
16 answers: 1 slip still gives three stars; up to 4, two stars.