Lesson 108: Abacus listening sums for kids
Level 9, Mind Castle. Listen to each number and add it on the abacus in your head.
What your child does, card by card
Listening sums. The numbers are spoken, not shown. PlayBuddy opens the lesson: “No numbers to see this time. Just listen.”
In Try it a green ring marks the next bead while your child works out the columns 2 + 3 + 4 and 8 + 2 - 3 + 4.
Flash sums in your head: the abacus is covered and the numbers appear one at a time, 1.1 seconds each (3 + 4 + 2 and 5 + 5 + 3); your child adds them in the head and picks the total from 9, 13 and 15.
Listening sums: nothing is shown. The browser’s voice reads each number (2 plus 3 plus 4, 6 plus 1 plus 5, 8 plus 2 minus 3 plus 4 and 7 plus 6 plus 5), and your child picks the total from 9, 11, 12 and 18. With the sound off, the numbers are shown instead.
You're ready! Listening sums: hear it, see the beads, add.
What this lesson trains
11 answers, roughly five minutes: 12 moves of the beads, 4 of them with the top bead and 8 with bottom beads. Numbers reach 11, so the tens rod and the ones rod work. Then 2 quick looks in your head. Friends do 4 of the 5 sums, by +3 = +5 −2, +2 = −8 +10, −3 = −10 +7 and +4 = −6 +10.
The first thing your child does: work out the columns 2 + 3 + 4 and 8 + 2 - 3 + 4.
The sum sheet
In Column Tower the lower window is a sum sheet instead of the hands: the column written out one line under another, the line being worked in yellow, the lines done ticked, and the total once the last line is in. The beads keep the running total, so the abacus is never cleared in the middle of a column.
What PlayBuddy and PlayType say
PlayBuddy: “No numbers to see this time. Just listen.”
Stars
With 1 or fewer slips across the 11 answers your child earns three stars; 2 or fewer, two.