Mix Mountain — Lesson 70: Mix Mountain test
Column sums: three numbers →Lesson 70: Abacus mixed friends test for kids
Level 5, Mix Mountain. 12 sums and 3 in your head. Get 12 right for the Mountain Flag sticker.
What your child does, card by card
Mix Mountain test. Show what you know! PlayType opens the lesson: “Test time. No hints. Show what you know.”
Then the test itself, 12 tasks without a ring: work out 7 + 6, 5 + 8, 6 + 7, 5 + 9, 12 - 6, 13 - 7, 14 - 8, 14 - 9, 47 + 8, 52 - 8, 99 + 1 and 100 - 1. Each gets one try, and a counter above shows how far along your child is.
Then the beads hide and the sums 8 + 6, 13 - 6 and 99 + 1 are done in the head, the answer picked from 7, 14, 100 and 101.
You passed! Mix Mountain is done. Next: Column Tower!
What this lesson trains
15 answers, roughly five minutes: 40 moves of the beads, 14 of them with the top bead and 26 with bottom beads. The largest is 100: hundreds, tens and ones. Then 3 quick looks in your head. Friends do 12 of the 12 sums, by +6 = +1 −5 +10, +8 = +3 −5 +10, +7 = +2 −5 +10, +9 = +4 −5 +10, −6 = −10 +5 −1, −7 = −10 +5 −2, −8 = −10 +5 −3, −9 = −10 +5 −4, +8 = −2 +10, −8 = −10 +2, +1 = −9 +10 and −1 = −10 +9.
Fingers and hands
Below the abacus the drawn hands show zero and 5, 6, 7, 12, 13, 14, 44, 47, 52, 55 and 99 here, finger for bead: the left hand counts the tens, the right hand the ones.
+6 on the fingers: the right hand opens one finger and folds the thumb, then the left hand opens one more finger for the ten (+1 −5 +10). +8 on the fingers: the right hand opens 3 fingers and folds the thumb, then the left hand opens one more finger for the ten (+3 −5 +10). +7 on the fingers: the right hand opens 2 fingers and folds the thumb, then the left hand opens one more finger for the ten (+2 −5 +10). +9 on the fingers: the right hand opens 4 fingers and folds the thumb, then the left hand opens one more finger for the ten (+4 −5 +10). −6 on the fingers: the left hand closes one finger for the ten, then the right hand puts the thumb out and closes one finger (−10 +5 −1). −7 on the fingers: the left hand closes one finger for the ten, then the right hand puts the thumb out and closes 2 fingers (−10 +5 −2). −8 on the fingers: the left hand closes one finger for the ten, then the right hand puts the thumb out and closes 3 fingers (−10 +5 −3). −9 on the fingers: the left hand closes one finger for the ten, then the right hand puts the thumb out and closes 4 fingers (−10 +5 −4). +8 on the fingers: the right hand lets 2 go and the left hand opens one more finger for the ten (−2 +10). −8 on the fingers: the left hand closes one finger for the ten and the right hand shows 2 more (−10 +2). +1 on the fingers: the right hand lets 9 go and the left hand opens one more finger for the ten (−9 +10). −1 on the fingers: the left hand closes one finger for the ten and the right hand shows 9 more (−10 +9).
Above 99 the drawn hands rest, faded, because ten fingers stop at 99; the abacus keeps going.
What PlayBuddy and PlayType say
PlayType: “Test time. No hints. Show what you know.”
PlayBuddy: “Click Let's Begin, or press Enter!”
PlayBuddy: “Here comes the last one.”
PlayType: “Now do it in your head.”
The test and its sticker
15 answers, one try each, with no green ring and no help. 12 or more right give the Mountain Flag sticker; fewer, and PlayBuddy says “Not yet. One more try and you've got this!” and Play again glows. Nothing earned before is taken away.