Sharing Garden — Lesson 99: Sharing a three-digit number

What your child does, card by card

Sharing a three-digit number. 936 ÷ 4: hundreds, tens, then ones. PlayType opens the lesson: “Hundreds first, then tens, then ones.”

484 ÷ 4: hundreds, then tens, then ones. The beads work the column line by line, 484, 84, 4 and zero, while the sum sheet below lights each line and ticks it; “4 × 100 off: 84 left”, “4 × 20 off: 4 left”, “4 × 1 off: 0 left” and “Each gets 121” light up as the total grows. Like lesson 96, with one more rod.

First a reminder (“936 ÷ 4”): the beads build 936, 136, 36, 16 and 6, ring by ring, while your child watches. 1 hundred left joins the tens. 1 ten left joins the ones.

Try it: your child works out 846 ÷ 2 and 525 ÷ 5, with a green ring on the next bead to move.

Then a short practice without rings: work out 648 ÷ 3 and 728 ÷ 7, each round starting from its own number.

In your head: the abacus is covered and your child works out 800 ÷ 4, 600 ÷ 3 and 900 ÷ 3, picking each answer from 200, 300 and 400.

You're ready! Three-digit sharing, the biggest place first.

What this lesson trains

About five minutes and 23 answers. Altogether the child makes 30 bead moves (10 with the top bead, 20 with bottom beads). 4 of the 20 bead tasks end on zero. Numbers reach 846, so all three rods work. Then 3 quick looks in your head.

The first thing your child does: work out 846 ÷ 2 and 525 ÷ 5.

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

PlayType: “The tens left over join the ones.”

Stars

With 2 or fewer slips across the 23 answers your child earns three stars; 5 or fewer, two.